Solar cell module and manufacturing method thereof

ABSTRACT

A solar cell module comprises an upper cover plate, a front adhesive layer, a cell array, a back adhesive layer and a back plate superposed in sequence, the cell array comprising multiple cells, adjacent cells connected by a plurality of conductive wires, at least two conductive wires comprising the metal wire which extends reciprocally between surfaces of adjacent cells, the conductive wires being in contact with the cells, the front adhesive layer in direct contact with the conductive wires and filling between adjacent conductive wires.

The present application claims priority to the following 41 Chineseapplications, the entireties of all of which are hereby incorporated byreference.

-   -   1. Chinese Patent Application No. 201410608576.6, filed Oct. 31,        2014;    -   2. Chinese Patent Application No. 201410606607.4, filed Oct. 31,        2014;    -   3. Chinese Patent Application No. 201410606601.7, filed Oct. 31,        2014;    -   4. Chinese Patent Application No. 201410606675.0, filed Oct. 31,        2014;    -   5. Chinese Patent Application No. 201410608579.X, filed Oct. 31,        2014;    -   6. Chinese Patent Application No. 201410608577.0, filed Oct. 31,        2014;    -   7. Chinese Patent Application No. 201410608580.2, filed Oct. 31,        2014;    -   8. Chinese Patent Application No. 201410606700.5, filed Oct. 31,        2014;    -   9. Chinese Patent Application No. 201410608469.3, filed Oct. 31,        2014;    -   10. Chinese Patent Application No. 201510085666.6, filed Feb.        17, 2015;    -   11. Chinese Patent Application No. 201510217625.8, filed Apr. 3,        2015;    -   12. Chinese Patent Application No. 201510217609.9, filed Apr. 3,        2015;    -   13. Chinese Patent Application No. 201520276309.3, filed Apr. 3,        2015;    -   14. Chinese Patent Application No. 201510217687.9, filed Apr. 3,        2015;    -   15. Chinese Patent Application No. 201510219182.6, filed Apr. 3,        2015;    -   16. Chinese Patent Application No. 201510217617.3, filed Apr. 3,        2015;    -   17. Chinese Patent Application No. 201520278183.3, filed Apr. 3,        2015;    -   18. Chinese Patent Application No. 201510217573.4, filed Apr. 3,        2015;    -   19. Chinese Patent Application No. 201510219540.3, filed Apr. 3,        2015;    -   20. Chinese Patent Application No. 201510218489.4, filed Apr. 3,        2015;    -   21. Chinese Patent Application No. 201510218563.2, filed Apr. 3,        2015;    -   22. Chinese Patent Application No. 201510219565.3, filed Apr. 3,        2015;    -   23. Chinese Patent Application No. 201510219436.4, filed Apr. 3,        2015;    -   24. Chinese Patent Application No. 201510218635.3, filed Apr. 3,        2015;    -   25. Chinese Patent Application No. 201520277480.6, filed Apr. 3,        2015;    -   26. Chinese Patent Application No. 201510219366.2, filed Apr. 3,        2015;    -   27. Chinese Patent Application No. 201520278409.X, filed Apr. 3,        2015;    -   28. Chinese Patent Application No. 201510218697.4, filed Apr. 3,        2015;    -   29. Chinese Patent Application No. 201510219417.1, filed Apr. 3,        2015;    -   30. Chinese Patent Application No. 201510221302.6, filed Apr. 3,        2015;    -   31. Chinese Patent Application No. 201510219353.5, filed Apr. 3,        2015;    -   32. Chinese Patent Application No. 201520280778.2, filed Apr. 3,        2015;    -   33. Chinese Patent Application No. 201510219378.5, filed Apr. 3,        2015;    -   34. Chinese Patent Application No. 201520280868.1, filed Apr. 3,        2015;    -   35. Chinese Patent Application No. 201510218574.0, filed Apr. 3,        2015;    -   36. Chinese Patent Application No. 201510217616.9, filed Apr. 3,        2015;    -   37. Chinese Patent Application No. 201520278149.6, filed Apr. 3,        2015;    -   38. Chinese Patent Application No. 201510218562.8, filed Apr. 3,        2015;    -   39. Chinese Patent Application No. 201510218535.0, filed Apr. 3,        2015;    -   40. Chinese Patent Application No. 201510217551.8, filed Apr. 3,        2015; and    -   41. Chinese Patent Application No. 201520276534.7, filed Apr. 3,        2015.

The present application is relevant to the following 10 U.S.applications, filed concurrently with the present application, theentireties of which are hereby incorporated by reference.

-   -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-24), entitled “Solar Cell Array, Solar Cell Module And        Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-26), entitled “Solar Cell Array, Solar Cell Module And        Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-28), entitled “Solar Cell Module And Manufacturing Method        Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-29), entitled “Solar Cell Array, Solar Cell Module And        Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-32), entitled “Solar Cell Unit, Solar Cell Array, Solar        Cell Module And Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-33), entitled “Solar Cell Unit, Solar Cell Array, Solar        Cell Module And Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-34), entitled “Solar Cell Unit, Solar Cell Array, Solar        Cell Module And Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-35), entitled “Solar Cell Unit, Solar Cell Array, Solar        Cell Module And Manufacturing Method Thereof,” filed ______;    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-36), entitled “Solar Cell Unit, Solar Cell Array, Solar        Cell Module And Manufacturing Method Thereof,” filed ______; and    -   U.S. patent application Ser. No. ______ (Attorney Docket No.        14880-44), entitled “Method For Manufacturing Solar Cell        Module,” filed ______.

FIELD

The present disclosure relates to the field of solar cells, and moreparticularly, to solar cell modules and manufacturing methods thereof.

BACKGROUND

A solar cell module is one of the most important components of a solarpower generation device. Sunlight irradiates to a cell from its frontsurface and is converted to electricity within the cell. Primary gridlines and secondary grid lines are disposed on the front surface andcover part of the front surface of the cell, and then the part ofsunlight irradiating to the primary grid lines and the secondary gridlines cannot be converted into electric energy. Thus, the primary gridlines and the secondary grid lines need to be as fine as possible inorder for the solar cell module to receive more sunlight. However, theprimary grid lines and the secondary grid lines serve to conductcurrent, and in terms of resistivity, the finer the primary grid linesand the secondary grid lines are, the smaller the cross section areathereof is, which causes greater loss of electricity due to increasedresistivity. Therefore, the primary grid lines and the secondary gridlines must be designed to achieve a balance between light blocking andelectric conduction, and to take the cost into consideration.

The current solar cell module mainly has a structure of three primarygrid lines, and the primary grid lines are formed by printing silverpaste on the surface of the cell and sintering. In such a way, themanufacturing of the primary grid lines is a high cost but matureprocess.

Generally, the solar cell module utilizes solar cells with three primarygrid lines, and the solar cells are arranged in a matrix form, usuallyin the matrix form of 12×6 or 10×6 (i.e. n=12 or 10). Each row isconnected by a bus bar. In this connection mode, the current path islonger, along with greater resistance, which tends to cause insufficientwelding, and hence affects the photoelectric conversion efficiency ofthe solar cell module.

Generally, if there are more primary grid lines of the solar cell, thedistance between the secondary grid lines and the primary grid lineswill be shorter, along with less resistance of the cells connected inseries, and better electricity generation performance. However, when thenumber of the primary grid lines is increased, the width of the primarygrid lines is decreased (otherwise the shaded area is increased to lowerthe electricity generation efficiency), such that it is more difficultto weld the cells in series. Currently, at most five primary grid linesof the cells connected in series can be welded successfully, but theproduct of five primary grid lines is not commercialized because thecost performance is lower than the product of three primary grid lines.

The solar cell with multiple primary grid lines (over 10 primary gridlines) can only use the metal wire as the primary grid lines, ratherthan adopt the primary grid lines sintered by silver paste, due to thelimitations of series welding technology.

The selection of material for the metal wire shall take cost,conductivity and weldability into consideration. In common metals, theconductivity of copper is slightly lower than silver but has a muchlower cost than silver, so copper is given preference. However, theweldability of copper primary grid lines and silver secondary grid linesis not good at a low temperature, and the welding below 200° C. (toohigh temperature may damage the cells).

Moreover, the metal wire cannot only serve as the primary grid lines onordinary cells, but also as the welding strip to connect the ordinarycells. The metal wire bridges two adjacent cells—connecting the frontsurface of one cell with the back surface of the other cell toconstitute a series circuit.

Generally, the solar cell module utilizes solar cells with three primarygrid lines, and each row of cells is connected by a bus bar. In thisconnection mode, the current path is longer, along with greaterresistance, which tends to cause insufficient welding, and hence affectsthe photoelectric conversion efficiency of the solar cell module.

SUMMARY

In one aspect, a solar cell module includes an upper cover plate, afront adhesive layer, a cell array, a back adhesive layer and a backplate superposed in sequence, the cell array comprising multiple cells,adjacent cells connected by a plurality of conductive wires, at leasttwo conductive wires being constituted by the metal wire which extendsreciprocally between surfaces of adjacent cells, the conductive wiresbeing in contact with the cells, the front adhesive layer in directcontact with the conductive wires and filling between adjacentconductive wires.

In the solar cell module according to embodiments of the presentapplication, the conductive wires constituted by the metal wire whichextends reciprocally replace traditional primary grid lines and weldingstrips, so as to reduce the cost. The metal wire extends reciprocally todecrease the number of free ends of the metal wire and to save the spacefor arranging the metal wire, i.e. without being limited by the space.The number of the conductive wires constituted by the metal wire whichextends reciprocally may be increased considerably, which is easy tomanufacture, and thus is suitable for mass production. The frontadhesive layer contacts with the conductive wires directly and fillsbetween the adjacent conductive wires, which can effectively isolate theconductive wires from air and moisture to prevent the conductive wiresfrom oxidation to guarantee the photoelectric conversion efficiency.

In another aspect, a method for manufacturing a solar cell modulecomprises forming at least two conductive wires by a metal wire whichextends reciprocally between surfaces of cells and contacts with thesurfaces of the cells, such that the adjacent cells are connected by aplurality of conductive wires to constitute a cell array; superposing anupper cover plate, a front adhesive layer, the cell array, a backadhesive layer and a back plate in sequence, in which a front surface ofthe cell faces the front adhesive layer, such that the front adhesivelayer contacts with the conductive wires directly; and a back surface ofthe cell faces the back adhesive layer, and then laminating them, inwhich the front adhesive layer fills between adjacent conductive wires,so as to obtain the solar cell module.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of the presentdisclosure will become apparent and more readily appreciated from thefollowing descriptions of embodiments with reference to the drawings, inwhich:

FIG. 1A is a plan view of a solar cell array according to an embodimentof the present disclosure;

FIG. 1B is a plan view of a solar cell array according to anotherembodiment of the present disclosure;

FIG. 2A is a transverse sectional view of a solar cell array accordingto an embodiment of the present disclosure;

FIG. 2B is a transverse sectional view of a solar cell array accordingto another embodiment of the present disclosure;

FIG. 3A is a longitudinal sectional view of a solar cell array accordingto embodiments of the present disclosure;

FIG. 3B is a longitudinal sectional view of a solar cell array accordingto another embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a metal wire for forming a conductivewire according to embodiments of the present disclosure;

FIG. 5 is a plan view of a solar cell array according to anotherembodiment of the present disclosure;

FIG. 6 is a plan view of a solar cell array according to anotherembodiment of the present disclosure;

FIG. 7 is a schematic diagram of a metal wire extending reciprocallyaccording to embodiments of the present disclosure;

FIG. 8 is a schematic diagram of two cells of a solar cell arrayaccording to embodiments of the present disclosure;

FIG. 9 is a sectional view of a solar cell array formed by connecting,by a metal wire, the two cells according to FIG. 8;

FIG. 10 is a schematic diagram of a solar cell module according toembodiments of the present disclosure;

FIG. 11 is a sectional view of part of the solar cell module accordingto FIG. 10;

FIG. 12A is a schematic diagram of a solar cell array according toanother embodiment of the present disclosure;

FIG. 12B is a schematic diagram of a solar cell array according to yetanother embodiment of the present disclosure;

FIG. 13 is a schematic diagram of a metal wire under a strain inComparison Example 1;

FIG. 14 is a curve graph of relationship between the number ofconductive wires and photoelectric conversion efficiency in a solar cellarray according to embodiments of the present disclosure;

FIG. 15 is a schematic diagram of a solar cell array formed with twocells connected by a metal wire according to an embodiment of thepresent disclosure.

FIG. 16 is schematic diagram of the solar cell array shown in FIG. 13after the metal wire is cut.

FIG. 17 is s a schematic diagram of a solar cell array formed with twocells connected by a metal wire according to another embodiment of thepresent disclosure.

FIG. 18 is a schematic diagram of the solar cell array shown in FIG. 15after the metal wire is cut.

Reference numerals: 100 cell module  10 upper cover plate  20 frontadhesive layer  30 cell array  31 cell  31A first cell  31B second cell311 cell substrate 312 secondary grid line 312A front secondary gridline 312B back secondary grid line 313 back electric field 314 backelectrode  32(32C) conductive wire  32A front conductive wire  32B backconductive wire 321 metal wire body 322 connection material layer  33short grid line  34 clip  40 back adhesive layer  50 lower cover plate

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail andexamples of the embodiments will be illustrated in the drawings, wheresame or similar reference numerals are used to indicate same or similarmembers or members with same or similar functions. The embodimentsdescribed herein with reference to the drawings are explanatory, whichare used to illustrate the present disclosure, but shall not beconstrued to limit the present disclosure.

In prior art, the primary grid lines and the secondary grid lines of thesolar cells are made of expensive silver paste, which requires acomplicated and costly manufacturing process of the primary grid linesand the secondary grid lines. When the cells are connected into amodule, the primary grid lines on the front surface of a cell are weldedto the back electrodes of another adjacent cell by a solder strip.Consequently, the welding of the primary grid lines is complicated, andthe manufacturing cost of the cells is high.

In prior art, two primary grid lines are usually disposed on the frontsurface of the cell, and formed by applying silver paste to the frontsurface of the cell. The primary grid lines have a great width (forexample, up to over 2 mm), which consumes a large amount of silver, andmakes the cost high.

In prior art, a solar cell with three primary grid lines is provided,but still consumes a large amount of silver, and has a high cost.Moreover, three primary grid lines increase the shaded area, whichlowers the photoelectric conversion efficiency.

In addition, the number of the primary grid lines is limited by thesolder strip. The larger the number of the primary grid lines is, thefiner a single primary grid line is, and hence the solder strip needs tobe narrower. Therefore, it is more difficult to weld the primary gridlines with the solder strip and to produce the narrower solder strip,and thus the cost of the welding rises.

Consequently, from the perspective of lowering the cost and reducing theshaded area, in prior art, the silver primary grid lines printed on thecell are replaced with metal wires, for example, copper wires. Thecopper wires are welded with the secondary grid lines to output thecurrent. Since the silver primary grid lines are no longer used, thecost can be reduced considerably. The copper wire has a smaller diameterto reduce the shaded area, so the number of the copper wires can beraised up to 10. This kind of cell may be called a cell without primarygrid lines, in which the metal wire replaces the silver primary gridlines and solder strips in the traditional solar cells.

In prior art, there is a technical solution that the electricalconnection of the metal wire and the cells is formed by laminating atransparent film pasted with metal wires and the cells, i.e. multipleparallel metal wires being fixed on the transparent film by adhesion,then being stuck on the cell, and finally being laminated to contactwith the secondary grid lines on the cell. In other words, the metalwires are in contact with the secondary grid lines by the laminatingprocess, so as to output the current. However, in this technicalsolution, the transparent film weakens the absorption rate of light, anda plurality of parallel metal wires may be in bad connection with thecells, which may affect the electrical performance. Thus, the number ofthe metal wires needs to be increased. If the number of the metal wiresis increased, the absorption rate of light from the front surface isaffected, and the performance of the product is degraded. Consequently,the product in this technical solution is not promoted andcommercialized. Moreover, as said above, the number of the parallelmetal wires is limited by the distance between adjacent metal wires.

For example, metal wires may be fixed by a transparent film. Multipleprimary grid lines are arranged in parallel, and laminated onto thecells via the transparent film. When the transparent film is laminatedwith the primary grid lines, the laminating temperature is much lowerthan the melting temperature of the transparent film, so the transparentfilm cannot really be laminated with the cells due to the intervalsamong the primary grid lines, and there will be gap between thetransparent film and the cells, so as to cause poor airtightness of thecell module. Moreover, the photoelectric conversion efficiency of thecells will be greatly influenced due to oxidation of air and moisture.

Thus, in the field of solar cells, the structure of the solar cell isuncomplicated, but each component is crucial. The production of theprimary grid lines takes various aspects into consideration, such asshaded area, electric conductivity, equipment, process, cost, etc., andhence becomes a difficult and crucial issue in the solar celltechnology. In the market, a solar cell with two primary grid lines isreplaced with a solar cell with three primary grid lines in 2007 throughhuge efforts of those skilled in the art. A few factories came up with asolar cell with four primary grid lines around 2014. The concept ofmultiple primary grid lines is put forward in the recent years, butstill there is no relatively mature product.

After extensive research, the inventors of the present disclosure findsif a cell is manufacture in a way that multiple parallel metal wires aredrawn simultaneously, cut off, and then welded to the cellsimultaneously, due to limitations of sophistication of equipment andprocess, for example, the influence of stress, the solar cell is bent tosome extent when disposed at a free state, so the metal wire needs toremain strained to flatten the cell (a test proves that the minimumstrain is at least 2 N for a copper wire with a diameter of 0.2 mm). Inorder to keep the strain, each metal wire needs to be provided withclips or similar equipment at the two ends thereof, and the equipmentoccupies certain space, but the space in the cell is limited. Thus, inprior art, at most ten metal wires can be drawn, fixed and welded to asingle cell, and it will be difficult to increase the number of themetal wires. The larger the number of the metal wires is, the more freeends there are, such that the equipment needs to control more metalwires at the same time, which is demanding as for the wiredrawingequipment. Moreover, the space of the solar cells is limited. Forexample, the dimension of a single cell is 156 mm×156 mm. In suchlimited space, the multiple metal wires need to be controlled accuratelyat the same time, which is demanding as for the equipment, especially asfor the accuracy. Currently, it is still difficult to control and weldmultiple metal wires simultaneously in actual production, so the numberof the conductive wires is limited, usually at most about ten, which isdifficult to realize.

In order to solve the above problem, relevant patents (US20100275976 andUS20100043863) provide a technical solution that multiple metal wiresare fixed on a transparent film. That's to say, multiple parallel metalwires are fixed on the transparent film by adhesion; then, thetransparent film bound with the multiple parallel metal wires isattached to the cell; finally the metal wires contact with the secondarygrid lines on the cell by lamination. By this method, the multiple metalwires are fixed via the transparent film, which solves the problem ofcontrolling the multiple metal wires simultaneously, and furtherincreases the number of the metal wires. However, the technical solutionalmost abandons the welding process. That's to say, the metal wires arenot connected with the secondary grid lines by the welding process;instead, the metal wires contact with the secondary grid lines by thelaminating process, so as to output the current.

The above technical solution can further increase the number of themetal wires, but the transparent film may affect the light absorption,which causes certain degree of shading, and thus lowers thephotoelectric conversion efficiency.

Furthermore, the above technical solution cannot connect the metal wireswith the secondary grid lines by the welding process, because themelting temperature of the transparent film must be higher than thewelding temperature (usually around 140° C.). Otherwise the transparentfilm will melt in the process of welding, which may lose the function offixing the metal wires, and then the metal wires drift, resulting inpoor welding effects.

Moreover, it is known to those skilled in the art that the solar cellsin use are sealed to prevent moisture and air from penetrating thecells, which may cause corrosion and short circuits. The encapsulatingmaterial at present is EVA whose melting point is 70° C. to 80° C., muchlower than the welding temperature. If the welding process is employed,as said above, the melting temperature of the transparent film must behigher than the welding temperature, which is higher than the meltingpoint of the encapsulating material. Thus, in the encapsulating process,the encapsulating material (EVA) will melt at the encapsulatingtemperature, but the transparent film will not, such that the meltingencapsulating material cannot penetrate the solid transparent film tocompletely seal the cells. Hence, the sealing effect is poor, and theactual product tends to fail. In terms of encapsulating, the meltingtemperature of the transparent film needs to be lower than the weldingtemperature, which is an evident paradox.

Therefore, the technical solution of fixing the metal wires via thetransparent film cannot adopt the welding process to weld the metalwires with the secondary grid lines. The metal wires are merely incontact with the secondary grid lines on the cells, i.e. the metal wiresare only placed on the secondary grid lines. Thus, the connectionstrength of the metal wires and the secondary grid lines is so low thatthe metal wires tend to separate from the secondary grid lines in thelaminating process or in use, which causes bad contact, low efficiencyof the cells, or even failure thereof. Consequently, the product in thistechnical solution is not promoted and commercialized. There is norelatively mature solar cell without primary grid lines.

Especially, the metal wires are relatively fine and in a large number.Moreover, the metal wires are connected afterwards and have free ends.Due to the problem concerning the sophistication of the equipment, itcannot be guaranteed that the fine and many metal wires are connectedwith the cells in accurate positions, especially the accuracy of thepositions of the ends. In order to avoid short circuits caused by themetal wire extending beyond the cells, the conductive wires aregenerally formed in the cells, in which case part of the secondary gridlines at the edges of the cells cannot be connected with the conductivewires well, thereby resulting in current loss.

The present disclosure seeks to solve at least one of the problemsexisting in the related art to at least some extent.

The present disclosure provides a solar cell without primary grid lines,which needs neither primary grid line nor sold strip disposed on thecells, and thus lowers the cost. The solar cell without primary gridlines can be commercialized for mass production, easy to manufacturewith simple equipment, especially in low cost, and moreover have highphotoelectric conversion efficiency.

According to a first aspect of embodiments of the present disclosure, asolar cell module includes an upper cover plate, a front adhesive layer,a cell array, a back adhesive layer and a back plate superposed insequence, the cell array comprising a plurality of cells arranged in amatrix form of multiple rows and multiple columns, at least two rows ofthe cells being connected by a plurality of conductive wires, at leasttwo conductive wires being constituted by a metal wire which extendsreciprocally between surfaces of the cells in different rows, theconductive wires contacting with the cells, the front adhesive layerbeing in direct contact with the conductive wires and filling betweenadjacent conductive wires.

In the solar cell module according to embodiments of the presentdisclosure, the conductive wires constituted by the metal wire whichextends reciprocally replace traditional primary grid lines and weldingstrips, so as to reduce the cost. The front adhesive layer is in directcontact with the conductive wires and fills between adjacent conductivewires, so as to separate the conductive wires from air and moisture inthe outside world effectively, to avoid the oxidation of the conductivewires and to guarantee the photoelectric conversion efficiency.

According to a second aspect of embodiments of the present disclosure, amethod for manufacturing a solar cell module includes: arranging aplurality of cells into a cell array of multiple rows and multiplecolumns; forming at least two conductive wires by a metal wire whichextends reciprocally a surface of a cell in a first row and a surface ofa cell in a second row, such that the cells in different rows areconnected by the conductive wires; superposing an upper cover plate, afront adhesive layer, the cell array, a back adhesive layer and a backplate in sequence, in which a front surface of the cell faces the frontadhesive layer, such that the front adhesive layer contacts with theconductive wires directly; and a back surface of the cell faces the backadhesive layer, and laminating them, in which the front adhesive layerfills between adjacent conductive wires, so as to obtain the solar cellmodule.

According to another embodiment of the present disclosure, it isprovided a solar cell without primary grid lines, which needs neitherexpensive silver primary grid line nor sold strip disposed on the cells,and thus lowers the cost. The solar cell without primary grid lines canbe commercialized for mass production, easy to manufacture with simpleequipment, especially in low cost, and moreover have high photoelectricconversion efficiency.

According to a third aspect of embodiments of the present disclosure, asolar cell module includes an upper cover plate, a front adhesive layer,a cell array, a back adhesive layer and a back plate superposed insequence, the cell array comprising multiple cells, adjacent cellsconnected by a plurality of conductive wires, at least two conductivewires being constituted by the metal wire which extends reciprocallybetween surfaces of adjacent cells, the conductive wires being incontact with the cells, the front adhesive layer in direct contact withthe conductive wires and filling between adjacent conductive wires.

In the solar cell module according to embodiments of the presentdisclosure, the conductive wires constituted by the metal wire whichextends reciprocally replace traditional primary grid lines and weldingstrips, so as to reduce the cost. The metal wire extends reciprocally todecrease the number of free ends of the metal wire and to save the spacefor arranging the metal wire, i.e. without being limited by the space.The number of the conductive wires constituted by the metal wire whichextends reciprocally may be increased considerably, which is easy tomanufacture, and thus is suitable for mass production. The frontadhesive layer contacts with the conductive wires directly and fillsbetween the adjacent conductive wires, which can effectively isolate theconductive wires from air and moisture to prevent the conductive wiresfrom oxidation to guarantee the photoelectric conversion efficiency.

According to a fourth aspect of embodiments of the present disclosure, amethod for manufacturing a solar cell module includes: forming at leasttwo conductive wires by a metal wire which extends reciprocally betweensurfaces of cells and contacts with the surfaces of the cells, such thatthe adjacent cells are connected by a plurality of conductive wires toconstitute a cell array; superposing an upper cover plate, a frontadhesive layer, the cell array, a back adhesive layer and a back platein sequence, in which a front surface of the cell faces the frontadhesive layer, such that the front adhesive layer contacts with theconductive wires directly; and a back surface of the cell faces the backadhesive layer, and then laminating them, in which the front adhesivelayer fills between adjacent conductive wires, so as to obtain the solarcell module.

According to another embodiment of the present disclosure, it isprovided a solar cell without primary grid lines, and the number of theconductive wires disposed the cell can be increased up to 20 or evengreater. In the present disclosure, the conductive wires are constitutedby a few metal wires which extend reciprocally, so as to reduce the freeends. Consequently, the number of the metal wires is not limited by thespace, and more conductive wires may be disposed on the cell tofacilitate the welding between the multiple conductive wires and thesecondary grid lines on the cell. Meanwhile, in the solar cell withoutprimary grid lines of the present disclosure, the conductive wires andthe secondary grid lines are connected by welding, which is reliable andsimple to manufacture, and has good sealability and high efficiency.Thus, the solar cells satisfy the practical requirements and may becommercialized for mass production.

Thus, the present disclosure provides a solar cell array that is easy tomanufacture in low cost, and improves the photoelectric conversionefficiency.

The present disclosure further provides a solar cell module having theabove solar cell array. The solar cell module is easy to manufacture inlow cost, and improves the photoelectric conversion efficiency.

The present disclosure further provides a method for manufacturing thesolar cell module.

According to a fifth aspect of embodiments of the present disclosure, asolar cell array includes a plurality of cells arranged in an n×m matrixform, in which in a row of cells, adjacent cells are connected by aplurality of conductive wires, at least two conductive wires constitutedby a metal wire which extends reciprocally between surfaces of adjacentcells; in two adjacent rows of cells, a cell in a a^(th) row and a cellin a (a+1)^(th) row are connected by the plurality of conductive wires,and at least two conductive wires are constituted by a metal wireextending reciprocally between a surface of a cell in a a^(th) row and asurface of a cell in a (a+1)^(th) row, n representing a column, mrepresenting a row and m−1≧a≧1; a secondary grid line and a short gridline are disposed on a front surface of the cell, and the secondary gridline includes a middle secondary grid line intersected with theconductive wire and an edge secondary grid line non-intersected with theconductive wire, the short grid line being connected with the edgesecondary grid line and being connected with the conductive wire or atleast one middle secondary grid line. The metal wire is coated with awelding layer by which the metal wire is welded with the middlesecondary grid line.

In the solar cell array according to embodiments of the presentdisclosure, the conductive wires are constituted by the metal wire whichextends reciprocally. The conductive wires of this structure extendreciprocally between two adjacent cells in a winding way to form afolded shape, which is easy to manufacture in low cost, and can improvethe photoelectric conversion efficiency of the solar cell array.Moreover, the conductive wires are arranged in a winding way to avoidfailure of the whole conductive wires when a single primary grid linebreaks off or is insufficiently welded, so as to avoid instability ofthe cells. The conductive wires and the secondary grid lines are welded,such that the conductive wires in the solar cell module will not driftor be insufficiently welded, and the solar cell module obtainsrelatively high photoelectric conversion efficiency.

Further, the cells in each row are directly connected by the conductivewires, which will use fewer bus bars, and reduces the connectiondistance, resistance and insufficient welding. The conductive wires arearranged in a winding way to avoid all the problems due to cutting theconductive wires. Moreover, the short grid lines are disposed on part ofthe secondary grid lines at the edges of the shiny surface of the cell,so as to avoid partial current loss because the conductive wiresarranged in the winding way cannot reach the secondary grid lines at theedges of the cell. The primary grid liens are constituted by the metalwire coated with an alloy layer with a low melting point, so as toimprove welding performance of the conductive wires with the secondarygrid lines and/or back electrodes. The conductive wires in the solarcell module will not drift or be insufficiently welded, and haverelatively high photoelectric conversion efficiency.

According to a sixth aspect of embodiments of the present disclosure,the solar cell module includes an upper cover plate, a front adhesivelayer, a cell array, a back adhesive layer and a back plate superposedin sequence, the cell array being a solar cell array according to theabove embodiments.

According to a seventh aspect of embodiments of the present disclosure,a method for manufacturing a solar cell module includes: forming aplurality of conductive wires by a metal wire which extends reciprocallya surface of a first cell of a plurality of cells and a surface of asecond cell thereof, such that the adjacent cells are connected by theplurality of conductive wires to constitute a cell array, wherein theplurality of cells are arranged in an n×m matrix form; in a row ofcells, a metal wire extends reciprocally between a surface of a firstcell and a surface of a second cell adjacent to the first cell; in twoadjacent rows of cells, the metal wire extends reciprocally between asurface of a cell in a a^(th) row and a surface of a cell in a(a+1)^(th) row to obtain the cell array, n representing a column, mrepresenting a row and m−1≧a≧1, a secondary grid line and a short gridline being disposed on a front surface of the cell, the secondary gridline including a middle secondary grid line intersected with theconductive wire and an edge secondary grid line non-intersected with theconductive wire, the short grid line being connected with the edgesecondary grid line, and being connected with the conductive wire or atleast one middle secondary grid line, the metal wire being coated with awelding layer by which the metal wire is welded with the middlesecondary grid line; superposing an upper cover plate, a front adhesivelayer, the cell array, a back adhesive layer and a back plate insequence, in which a front surface of the cell faces the front adhesivelayer, a back surface thereof facing the back adhesive layer, andlaminating them to obtain the solar cell module.

The winding method in the present disclosure facilitates electricalconnection of the metal wire with the cell, and the good connectionperformance is beneficial, especially, to welding of the metal wire withthe cell, and can avoid insufficient welding of the conductive wires.The solar cell manufactured has beautiful design and good performance.Moreover, a suitable number of conductive wires can be manufactured, aslong as they are strained by two clips, which is independent from spacelimit. The process is easy to realize with simple equipment, which canbe industrialized. The edge secondary grid lines at the edges of thecell which are not intersected with the conductive wires areelectrically with the conductive wires, so as to reduce current loss.The short grid lines can be formed by screen printing silver, which iseasy to realize and to control with high accuracy. The electricconnection of all the fine grid lines and the conductive wires can beguaranteed, which lowers the sophistication and difficulty of theprocess, and improves the photoelectric conversion efficiency of thecell considerably.

According to another embodiment of the present disclosure, it is furtherprovided a solar cell module having the above solar cell array. Thesolar cell module is easy to manufacture in low cost, and improves thephotoelectric conversion efficiency.

The present disclosure further provides a method for manufacturing thesolar cell module.

According to an eighth aspect of embodiments of the present disclosure,a solar cell array includes a plurality of cells, adjacent cellsconnected by a plurality of conductive wires constituted by a metalwire. At least one metal wire extends reciprocally between a surface ofa first cell of the adjacent cells and a surface of a second cellthereof, and breaks off at a turn after being connected with the cells.

In the solar cell array according to embodiments of the presentdisclosure, the conductive wires are constituted by the metal wire whichextends reciprocally. The metal wire extends reciprocally between twoadjacent cells in a winding way to form a folded shape, and then iswelded with the cell. After welding, the above metal wire is cut off atthe turns thereof. The conductive wires of this structure are easy tomanufacture in low cost, and can improve the photoelectric conversionefficiency of the solar cell array.

In addition, the metal wire breaks off at the turns, which can reducestress upon the metal wire at the turns, and guarantee the weldingeffect.

According to a ninth aspect of embodiments of the present disclosure,the solar cell module includes an upper cover plate, a front adhesivelayer, a cell array, a back adhesive layer and a back plate superposedin sequence, the cell array being a solar cell array according to theabove embodiments.

According to a tenth aspect of embodiments of the present disclosure, amethod for manufacturing a solar cell module includes: forming at leasttwo conductive wires by a metal wire which extends reciprocally betweena surface of a first cell and a surface of a second cell adjacent to thefirst cell, welding the metal wire with secondary grid lines on thefront surface of the cell, such that adjacent cells are connected by theplurality of conductive wires; breaking the metal wire at a turn thereofto obtain a cell array; superposing an upper cover plate, a frontadhesive layer, the cell array, a back adhesive layer and a back platein sequence, in which a front surface of the cell faces the frontadhesive layer, a back surface thereof facing the back adhesive layer,and laminating them to obtain the solar cell module.

The winding method in the present disclosure facilitates electricalconnection of the metal wire with the cell, and the good connectionperformance is beneficial, especially, to welding of the metal wire withthe cell, and can avoid insufficient welding of the conductive wires.The solar cell manufactured has beautiful design and good performance.Moreover, a suitable number of conductive wires can be manufactured, aslong as they are strained by two clips, which is independent from spacelimit. The process is easy to realize with simple equipment, which canbe industrialized.

Part of technical terms in the present disclosure will be elaboratedherein for clarity and convenience of description.

According to one embodiment of the present disclosure, referring toFIGS. 1-18, cell 31 includes a cell substrate 311, secondary grid lines312 disposed on a front surface (the surface on which light is incident)of the cell substrate 311, a back electric field 313 disposed on a backsurface of the cell substrate 311, and back electrodes 314 disposed onthe back electric field 313. Thus, the secondary grid lines 312 can becalled the secondary grid lines 312 of the cell 31, the back electricfield 313 called the back electric field 313 of the cell 31, and theback electrodes 314 called the back electrodes 314 of the cell 31.

Cell substrate 311 can be an intermediate product obtained bysubjecting, for example, a silicon chip to processes of felting,diffusing, edge etching and silicon nitride layer depositing. However,it shall be understood that the cell substrate 311 in the presentdisclosure is not limited to be formed by the silicon chip, but includesa thin-film solar cell substrate or any other suitable solar cellsubstrate 311.

In other words, the cell 31 comprises a silicon chip, some processinglayers on a surface of the silicon chip, secondary grid lines on a frontsurface, and a back electric field 313 and back electrodes 314 on a backsurface, or includes other equivalent solar cells of other types withoutany front electrode, for instance, various film cells—a-Si film cell,CdTe solar cell, CIGS solar cell, GaAs solar cell, Nano-TiO₂dye-sensitized solar cell (DSSC) etc.

Cell unit includes a cell 31 and conductive wires 32 constituted by ametal wire S.

A solar cell array 30 includes a plurality of cells 31 and conductivewires 32 which connect adjacent cells 31 and are constituted by themetal wire S. In other words, the solar cell array 30 is formed of aplurality of cells 31 connected by the conductive wires 32.

In the solar cell array 30, the metal wire S constitutes the conductivewires 32 of the cell unit, and extends between surfaces of the adjacentcells 31, which shall be understood in a broad sense that the metal wireS may extend between front surfaces of the adjacent cells 31, or mayextend between a front surface of a first cell 31 and a back surface ofa second cell 31 adjacent to the first cell 31. When the metal wire Sextends between the front surface of the first cell 31 and the backsurface of the second cell 31 adjacent to the first cell 31, theconductive wires 32 may include front conductive wires 32A extending onthe front surface of the cell 31 and electrically connected with thesecondary grid lines 312 of the cell 31, and back conductive wires 32Bextending on the back surface of the cell 31 and electrically connectedwith the back electrodes 314 of the cell 31. Part of the metal wire Sbetween the adjacent cells 31 can be called connection conductive wires.

In the present disclosure, the cell substrate 311, the cell 31, the cellunit, the cell array 30 and the solar cell module are only for theconvenience of description, and shall not be construed to limit thepresent disclosure.

All the ranges disclosed in the present disclosure include endpoints,and can be individual or combined. It shall be understood that theendpoints and any value of the ranges are not limited to an accuraterange or value, but also include values proximate the ranges or values.

In the present disclosure, orientation terms such as “upper” and “lower”usually refer to the orientation “upper” or “lower” as shown in thedrawings under discussion, unless specified otherwise; “front surface”refers to a surface of the solar cell module facing the light when themodule is in operation, i.e. a surface on which light is incident, while“back surface” refers to a surface of the solar cell module back to thelight when the module is in operation.

In the following, a solar cell module 100 according to the embodimentsof the present disclosure will be described with respect to thedrawings.

As shown in FIG. 1 to FIG. 11, the solar cell module 100 according tothe embodiments of the present disclosure includes an upper cover plate10, a front adhesive layer 20, a cell array 30, a back adhesive layer 40and a back plate 50. The cell array 30 includes a plurality of cells 31which are arranged into a matrix form of multiple rows and multiplecolumns. At least two rows of cells 31 are connected by a plurality ofconductive wires 32, and at least two conductive wires 32 areconstituted by a metal wire S which extends reciprocally betweensurfaces of the cells in different rows. The conductive wires 32 are incontact with the cells 31. The front adhesive layer 20 is in directcontact with the conductive wires 32 and fills between adjacentconductive wires 32.

In the same row of cells, adjacent cells 31 are connected by theplurality of conductive wires 32. At least two conductive wires 32 areconstituted by the metal wire S which extends reciprocally betweensurfaces of the adjacent cells. The metal wire S extends reciprocallybetween a surface of a first cell 31 and a surface of a second cell 31adjacent to the first cell 31.

Alternatively, as shown in FIG. 1 to FIG. 11, the solar cell module 100according to the embodiments of the present disclosure includes an uppercover plate 10, a front adhesive layer 20, a cell array 30, a backadhesive layer 40 and a back plate 50. The cell array 30 includes aplurality of cells 31. The adjacent cells 31 are connected with aplurality of conductive wires 32. At least two conductive wires 32 areconstituted by the metal wire S which extends reciprocally betweensurfaces of adjacent cells. The conductive wires 32 are in contact withthe cells 31; the front adhesive layer 20 contacts with the conductivewires 32 directly and fills between the adjacent conductive wires 32.

In other words, the solar cell module 100 according to the embodimentsof the present disclosure includes the upper cover plate 10, the frontadhesive layer 20, the cell array 30, the back adhesive layer 40 and theback plate 50 superposed sequentially along a direction from up to down.The cell array 30 includes a plurality of cells 31 and conductive wires32 for connecting the plurality of cells 31. At least two conductivewires 32 are constituted by the metal wire S which extends reciprocallybetween surfaces of two adjacent cells 31.

Alternatively, as shown in FIG. 1B, FIG. 2B, FIG. 3B and FIG. 12B, thesolar cell array 30 according to the embodiments of the presentdisclosure comprises a plurality of cells 31 arranged in an n×m matrixform. In a row of cells 31, a metal wire extends reciprocally between asurface of a first cell 31 and a surface of a second cell 31 adjacent tothe first cell 31 to form a plurality of conductive wires 32, theadjacent cells 31 being connected by the plurality of conductive wires32.

In two adjacent rows of cells 31, the metal wire extends reciprocallybetween a surface of a cell 31 in a a^(th) row and a surface of a cell31 in a (a+1)^(th) row to connect the cells in two adjacent rows, inwhich n represents a column, m represents a row, and m−1≧a≧1.

The present disclosure is not limited to that multiple conductive wires32 are formed by winding the metal wire—the conductive wires can bepartially or completely formed by winding the metal wire. In otherwords, part of the conductive wires can be formed by non-winded metalwires. The present disclosure aims to reduce free ends, to enlargeoperation space. The reciprocal extension can be back and forth once.There is no limit to the termination point of the reciprocalextension—the starting point and the termination point can be at thesame cell or at different cells, as long as the metal wire is winded.

Secondary grid lines 312 and short grid lines 33 are disposed on a frontsurface of the cell 31, the secondary grid lines 312 include middlesecondary grid lines 3122 intersected with the conductive wires 32 andedge secondary grid lines 3121 non-intersected with the conductive wires32; the short grid lines 33 are connected with the edge secondary gridlines 3121, and are connected with the conductive wires 32 or at leastone middle secondary grid line 3122. The metal wire is coated with awelding layer by which the metal wire is welded with the middlesecondary grid lines 3122.

In other words, the solar cell array 30 according to the embodiments ofthe present disclosure is formed with at least four cells 31 which arearranged in a matrix form of two columns and two rows. Two adjacentcells 31 in the same row are connected by a plurality of conductivewires 32 constituted by the metal wire S which extends reciprocallybetween two adjacent cells 31. Two adjacent cells 31 in the same columnare connected by a plurality of conductive wires 32 constituted by themetal wire S which extends reciprocally between two adjacent cells 31.

Each cell 31 comprises a cell substrate 311, secondary grid lines 312and short lines 33 disposed on a front surface of the cell substrate311, and back electrodes 314 disposed on a back surface of the cellsubstrate 311. Adjacent cells 31 are connected by a plurality ofconductive wires 32 constituted by a metal wire S which extendsreciprocally between the adjacent cells 31.

The secondary grid lines 312 located at a side surface of the cellsubstrate 311 comprises two parts—one part of the secondary grid lines312 intersected with the conductive wires 32 and located in a middleposition of the cell substrate 311 to form middle secondary grid lines3122; the other part of the secondary grid lines 312 non-intersectedwith the conductive wires 32 and located at an edge of one side awayfrom the conductive wires 32 to form edge secondary grid lines 3121.

The edge secondary grid lines 3121 are provided with short grid lines 33connected with the conductive wires 32 or at least one middle secondarygrid line 3122. The short grid lines 33 are located at the edges of thecell 31 where the conductive wires 32 cannot reach when being winded, soas to avoid current loss.

That's to say, each cell 31 is provided with secondary grid lines 312and short grid lines 33 on the front surface of the cell, and providedwith back electrodes 314 on the back surface thereof. The two adjacentcells are connected by the plurality of conductive wires 32. Theconductive wires 32 are constituted by the metal wire which extendsreciprocally between two adjacent cells, and are provided with a weldinglayer for being welded with the secondary grid lines 312. The conductivewires 32 are welded with the secondary grid lines 312.

In the solar cell array according to embodiments of the presentdisclosure, the conductive wires are constituted by the metal wire whichextends reciprocally. The conductive wires of this structure extendreciprocally between two adjacent cells in a winding way to form afolded shape, which is easy to manufacture in low cost, and can improvethe photoelectric conversion efficiency of the solar cell array.Moreover, the conductive wires are arranged in a winding way to avoidfailure of the whole conductive wires when a single primary grid linebreaks off or is insufficiently welded, so as to avoid instability ofthe cells. The conductive wires and the secondary grid lines are welded,such that the conductive wires in the solar cell module will not driftor be insufficiently welded, and the solar cell module obtainsrelatively high photoelectric conversion efficiency. Further, the cellsin each row are directly connected by the conductive wires, which willuse fewer bus bars, and reduces the connection distance, resistance andinsufficient welding. The conductive wires are arranged in a winding wayto avoid all the problems due to cutting the conductive wires. Moreover,the short grid lines are disposed on part of the secondary grid lines atthe edges of the shiny surface of the cell, so as to avoid partialcurrent loss because the conductive wires arranged in the winding waycannot reach the secondary grid lines at the edges of the cell. Theprimary grid liens are constituted by the metal wire coated with analloy layer with a low melting point, so as to improve weldingperformance of the conductive wires with the secondary grid lines and/orback electrodes. The conductive wires in the solar cell module will notdrift or be insufficiently welded, and have relatively highphotoelectric conversion efficiency.

The present disclosure is not limited to that all the conductive wiresare formed by winding the metal wire—the conductive wires can bepartially or completely formed by winding the metal wire. The reciprocalextension can be back and forth once. There is no limit as to thetermination point of the reciprocal extension—the starting point and thetermination point can be at the same cell or at different cells, as longas the metal wire is winded.

Specifically, the solar cell module 100 according to the embodiments ofthe present disclosure includes the upper cover plate 10, the frontadhesive layer 20, the cell array 30, the back adhesive layer 40 and theback plate 50 superposed sequentially along a direction from up to down.The cell array 30 comprises four cells 31 arranged into at least tworows and two columns, in which the two adjacent cells 31 in the same roware connected by the plurality of conductive wires 32 constituted by themetal wire S. The metal wire S extends reciprocally between surfaces oftwo adjacent cells 31. The adjacent cells 31 in the same column are alsoconnected by the plurality of conductive wires 32 constituted by themetal wire S. The metal wire S extends reciprocally between surfaces oftwo adjacent cells 31.

The conductive wires 32 are electrically connected with the cells 31, inwhich the front adhesive layer 20 on the cells 31 contacts with theconductive wires 32 directly and fills between the adjacent conductivewires 32, such that the front adhesive layer 20 can fix the conductivewires 32, and separate the conductive wires 32 from air and moisturefrom the outside world, so as to prevent the conductive wires 32 fromoxidation and to guarantee the photoelectric conversion efficiency.

Thus, in the solar cell module 100 according to embodiments of thepresent disclosure, the conductive wires 32 constituted by the metalwire S which extends reciprocally replace traditional primary grid linesand solder strips, so as to reduce the cost. The metal wire S extendsreciprocally to decrease the number of free ends of the metal wire S andto save the space for arranging the metal wire S, i.e. without beinglimited by the space. The number of the conductive wires 32 constitutedby the metal wire which extends reciprocally may be increasedconsiderably, which is easy to manufacture, and thus is suitable formass production. The front adhesive layer 20 contacts with theconductive wires 32 directly and fills between the adjacent conductivewires 32, which can effectively isolate the conductive wires from airand moisture to prevent the conductive wires 32 from oxidation toguarantee the photoelectric conversion efficiency.

The front adhesive layer 20 and the back adhesive layer 40 are adhesivelayers commonly used in the art. Preferably, the front adhesive layer 20and the back adhesive layer 40 are polyethylene-octene elastomer (POE)and/or ethylene-vinyl acetate copolymer (EVA). In the presentdisclosure, polyethylene-octene elastomer (POE) and/or ethylene-vinylacetate copolymer (EVA) are conventional products in the art, or can beobtained in a method known to those skilled in the art.

In the embodiments of the present disclosure, the upper cover plate 10and the back plate 50 can be selected and determined by conventionaltechnical means in the art. Preferably, the upper cover plate 10 and theback plate 50 can be transparent plates respectively, for example, glassplates.

In the process of manufacturing the solar cell module 100, theconductive wires can be first bound or welded with the secondary gridlines and the conductive adhesive of the back electrodes of the cell 31,and then superposed and laminated.

Other components of the solar cell module 100 according to the presentdisclosure are known in the art, which will be not described in detailherein.

In the following, a solar cell array 30 according to the embodiments ofthe present disclosure will be described with respect to the drawings.

Specifically, the solar cell array 30 according to the embodiments ofthe present disclosure includes a plurality of cells 31 which arearranged into a matrix form of multiple rows and multiple columns. Atleast two rows of cells 31 are connected by a metal wire S which extendsreciprocally between surfaces of the cells in different rows andconstitutes conductive wires 32.

Alternatively, the solar cell array 30 according to the embodiments ofthe present disclosure includes a plurality of cells 31. The adjacentcells 31 are connected with a plurality of conductive wires 32 which areconstituted by a metal wire S. The metal wire S is electricallyconnected with the cells 31 and extends reciprocally between thesurfaces of the adjacent cells 31.

A cell unit is formed by the cell 31 and the conductive wires 32constituted by the metal wire S which extends on the surface of the cell31. In other words, the solar cell array 30 according to the embodimentsof the present disclosure is formed with a plurality of cell units; theconductive wires 32 of the plurality of cells are formed by the metalwire S which extends reciprocally between the surfaces of the cells 31.

It shall be understood that the term “extending reciprocally” in thisdisclosure can be called “winding” which means that the metal wire Sextends between the surfaces of the cells 31. For example, referring toFIG. 1, in some circumstances, the metal wire extends between thesurfaces of the cells 31 in the same plane, such as either between thefront surfaces or between the bottom surfaces of the cells, to form aserpentine pattern. In some other circumstances, the metal wire Sextends between the surfaces of the cells 31 in multiple planes, such asbetween both the front surface of a cell and the bottom surface of anadjacent cell, to form a serpentine pattern. In yet other circumstances,the metal wire S extends between the surfaces of the cells 31 both inthe same plane and in multiple planes, such as sometimes between eitherthe front surfaces or the bottom surfaces of some adjacent cells, and atother times between both the front surface of a certain cell and thebottom surface of an adjacent cell, to form a serpentine pattern. Theplurality of conductive wires equals two or more passes of theserpentine shaped pattern. Preferably, two or more passes of theserpentine shaped pattern on the same plane are substantially parallelto each other. More preferably, all the passes of the serpentine shapedpattern on the same plane are substantially parallel to each other.

In the present disclosure, it shall be understood in a broad sense that“the metal wire S extends reciprocally between surfaces of the cells 31.For example, the metal wire S may extend reciprocally between a frontsurface of a first cell 31 and a back surface of a second cell 31adjacent to the first cell 31; the metal wire S may extend from asurface of the first cell 31 through surfaces of a predetermined numberof middle cells 31 to a surface of the last cell 31, and then extendsback from the surface of the last cell 31 through the surfaces of apredetermined number of middle cells 31 to the surface of the first cell31, extending reciprocally like this.

In addition, when the cells 31 are connected in parallel by the metalwire S, the metal wire S can extend on front surfaces of the cells 31,such that the metal wire S constitutes front conductive wires 32A.Alternatively, a first metal wire S extends reciprocally between thefront surfaces of the cells 31, and a second metal wire S extendsreciprocally between the back surfaces of the cells 31, such that thefirst metal wire S constitutes front conductive wires 32A, and thesecond metal wire S constitutes back conductive wires 32B.

When the cells 31 are connected in series by the metal wire S, the metalwire S can extend reciprocally between a front surface of a first cell31 and a back surface of a second cell 31 adjacent to the first cell 31,such that part of the metal wire S which extends on the front surface ofthe first cell 31 constitutes front conductive wires 32A, and partthereof which extends on the back surface of the second cell 31constitutes back conductive wires 32B. In the present disclosure, unlessspecified otherwise, the conductive wires 32 can be understood as thefront conductive wires 32A, the back conductive wires 32B, or thecombination thereof.

The term “extending reciprocally” can be understood as that the metalwire S extends reciprocally once to form two conductive wires 32 whichare formed by winding a metal wire S. For example, two adjacentconductive wires form a U-shape structure or a V-shape structure, yetthe present disclosure is not limited to the above.

In the solar cell array 30 according to the embodiments of the presentdisclosure, the conductive wires 32 of the plurality of cells 31 areconstituted by the metal wire S which extends reciprocally; and theadjacent cells 31 are connected by the conductive wires 32. Hence, thecells are not necessarily printed with expensive silver primary girdlines on the surfaces thereof, and can be manufactured in a simplemanner without using a solder strip to connect the cells. It isconvenient to connect the metal wire S with the secondary grid lines andthe back electrodes, so that the cost of the cells is reducedconsiderably.

Moreover, since the conductive wires 32 are constituted by the metalwire S which extends reciprocally, the width of the conductive wires 32(i.e. the width of projection of the metal wire on the cell) may bedecreased, thereby decreasing the shaded area of the front surface.Further, the number of the conductive wires 32 can be adjusted easily,and thus the resistance of the conductive wires 32 is reduced, comparedwith the primary grid lines made of the silver paste, and thephotoelectric conversion efficiency is improved. Since the metal wire Sextends reciprocally to form the conductive wires, when the cell array30 is used to manufacture the solar cell module 100, the metal wire Swill not tend to shift, i.e. the metal wire is not easy to “drift”,which will not affect but further improve the photoelectric conversionefficiency.

Therefore, the solar cell array 30 according to the embodiments of thepresent disclosure has low cost and high photoelectric conversionefficiency.

In some specific embodiments of the present disclosure, in the same rowof cells 31, the metal wire S extends reciprocally between a surface ofa first cell 31 and a surface of a second cell 31 adjacent to the firstcell 31.

Alternatively, in the present disclosure, the metal wire S extendsreciprocally between a front surface of the first cell 31 and a backsurface of the second cell 31 adjacent to the first cell 31. The frontadhesive layer 20 directly contacts with the conductive wires 32 on thefront surface of the first cell 31 and fills between the adjacentconductive wires 32 on the front surface of the first cell 31. The backadhesive layer 40 directly contacts with the conductive wires 32 on theback surface of the second cell 31 and fills between the adjacentconductive wires 32 on the back surface of the second cell 31.

In other words, in the present disclosure, the two adjacent cells 31 areconnected by the metal wire S. In the two adjacent cells 31, the frontsurface of the first cell 31 is connected with the metal wire S, and theback surface of the second cell 31 is connected with the metal wire S.

The front adhesive layer 20 on the first cell 31 whose front surface isconnected with the metal wire S is in direct contact with the metal wireS on the front surface of the first cell 31 and fills between theadjacent conductive wires 32. The back adhesive layer 40 on the secondcell 31 whose back surface is connected with the metal wire S is indirect contact with the metal wire S on the back surface of the secondcell 31 and fills between the adjacent conductive wires 32 (as shown inFIG. 2).

Consequently, in the solar cell module 100 according to the presentdisclosure, not only the front adhesive layer 20 can separate theconductive wires 32 on the front surfaces of part of the cells 31 fromthe outside world, but also the back adhesive layer 40 can separate theconductive wires 32 on the back surfaces of part of the cells 31 fromthe outside world, so as to further guarantee the photoelectricconversion efficiency of the solar cell module 100.

Alternatively, the conductive wires 32 located on the back surface ofthe second cell 31 are electrically connected with the back electrodes314 of the second cell 31.

That's to say, the metal wire S extends reciprocally between a frontsurface of a first cell 31 and a back surface of a second cell 31adjacent to the first cell 31. The metal wire S forms front conductivewires 32A on the front surface of the first cell 31, and forms backconductive wires 32B on the back surface of the second cell 31. The backconductive wires 32B located on the back surface of the second cell 31are electrically connected with the back electrodes 314 of the secondcell 31, so as to guarantee the effect of connecting the metal wire Sand the second cell 31.

In the following, the solar cell array 30 according to specificembodiments of the present disclosure will be described with referenceto the drawings.

The solar cell array 30 according to a specific embodiment of thepresent disclosure is illustrated with reference to FIG. 1 to FIG. 3.

In the embodiment shown in FIG. 1 to FIG. 3, two cells 31 in the solarcell array 30 are shown. In other words, it shows two cells 31 connectedwith each other via the conductive wires 32 constituted by the metalwire S.

It can be understood that the cell 31 comprises a cell substrate 311,secondary grid lines 312 (i.e. front secondary grid lines 312A) disposedon a front surface of the cell substrate 311, a back electric field 313disposed on a back surface of the cell substrate 311, and backelectrodes 314 disposed on the back electric field 313. In the presentdisclosure, it shall be understood that the back electrodes 314 may beback electrodes of a traditional cell, for example, printed by thesilver paste, or may be back secondary grid lines 312B similar to thesecondary grid lines on the front surface of the cell substrate, or maybe multiple discrete welding portions, unless specified otherwise. Thesecondary grid lines refer to the secondary grid lines 312 on the frontsurface of the cell substrate 311, unless specified otherwise.

As shown in FIG. 1 to FIG. 3, the solar cell array in the embodimentincludes two cells (called a first cell 31A and a second cell 31Brespectively for convenience of description). The metal wire S extendsreciprocally between the front surface of the first cell 31A (a shinysurface, i.e. an upper surface in FIG. 2) and the back surface of thesecond cell 31B, such that the metal wire S constitutes front conductivewires of the first cell 31A and back conductive wires of the second cell31B. The metal wire S is electrically connected with the secondary gridlines of the first cell 31A (for example, being welded or bound by aconductive adhesive), and electrically connected with the backelectrodes of the second cell 31B.

In some embodiments, the metal wire extends reciprocally between thefirst cell 31A and the second cell 31B for 10 to 60 times to form 20 to120 conductive wires. Preferably, as shown in FIG. 1, the metal wireextends reciprocally for 12 times to form 24 conductive wires 32, andthere is only one metal wire. In other words, a single metal wireextends reciprocally for 12 times to form 24 conductive wires, and thedistance of the adjacent conductive wires can range from 2.5 mm to 15mm. In this embodiment, the number of the conductive wires is increased,compared with the traditional cell, such that the distance between thesecondary grid lines and the conductive wires which the current runsthrough is decreased, so as to reduce the resistance and improve thephotoelectric conversion efficiency. In the embodiment shown in FIG. 1,the adjacent conductive wires form a U-shape structure, for convenienceof winding the metal wire. Alternatively, the present disclosure is notlimited to the above. For example, the adjacent conductive wires canform a V-shape structure.

As shown in FIG. 14, it shows the relationship between the number of theconductive wires and the photoelectric conversion efficiency of the cellmodule. It can be seen from FIG. 14 that the photoelectric conversionefficiency of the cell module is relatively high when the number of theconductive wires 32 ranges from 20 to 30.

More preferably, as shown in FIG. 4, the metal wire S includes a metalwire body 321 and a connection material layer 322 coating the outersurface of the metal wire body, and the connection material layer 322can be a conductive adhesive layer or a welding layer. The metal wire iswelded with the secondary grid lines and/or the back electrodes by thewelding layer, such that it is convenient to electrically connect themetal with the secondary grid lines and/or the back electrodes, and toavoid drifting of the metal wire in the connection process so as toguarantee the photoelectric conversion efficiency. Of course, theelectrical connection of the metal with the cell substrate can beconducted during or before the laminating process of the solar cellmodule, and preference is given to the latter.

It shall be noted that in the present disclosure, the metal wire Srefers to a metal wire for extending reciprocally on the cells 31 toform the conductive wires 32; and the conductive wires 32 include ametal wire body 321 and a connection material layer 322 coating themetal wire body 321, i.e. the metal wire S consists of the metal wirebody 321 and the connection material layer 322 coating the metal wirebody 321. In the embodiments of the present disclosure, unless specifiedotherwise, the metal wire represents the metal wire S which extendsreciprocally on the cells to form the conductive wires 32.

In some embodiments, preferably, the metal wire body 321 is a copperwire. Of course, the metal wire S can be a copper wire, too. In otherwords, the metal wire does not include the connection material layer322, but the present disclosure does not limited thereto. For example,the metal wire body 321 can be an aluminum wire. Preferably, the metalwire S has a circular cross section, such that more sunlight can reachthe cell substrate to further improve the photoelectric conversionefficiency.

In some embodiments, preferably, before the metal wire contact thecells, the metal wire extends under a strain, i.e. straightening themetal wire. After the metal wire is connected with the secondary gridlines and the back electrodes of the cell, the strain of the metal wirecan be released, so as to further avoid the drifting of the conductivewires when the solar cell module is manufactured, and to guarantee thephotoelectric conversion efficiency.

FIG. 5 is a schematic diagram of a solar cell array according to anotherembodiment of the present disclosure. As shown in FIG. 5, the metal wireextends reciprocally between the front surface of the first cell 31A andthe front surface of the second cell 31B, such that the metal wireconstitutes front conductive wires of the first cell 31A and frontconductive wires of the second cell 31B. In such a way, the first cell31A and the second cell 31B are connected in parallel. Of course, it canbe understood that preferably the back electrodes of the first cell 31Aand the back electrodes of the second cell 31B can be connected via backconductive wires constituted by another metal wire which extendsreciprocally. Alternatively, the back electrodes of the first cell 31Aand the back electrodes of the second cell 31B can be connected in atraditional manner.

According to an embodiment of the present disclosure, the adjacent cells31 are connected by a plurality of conductive wires 32 constituted bythe metal wire which extends between a surface of a first cell 31 and asurface of a second cell 31 adjacent to the first cell 31.

Alternatively, the metal wire breaks off at a turn after being connectedwith the cells 31.

Preferably, the short grid lines 33 are connected with the edgesecondary grid line 3121 closest to the middle secondary grid lines3122.

In some other specific embodiments of the present disclosure, the shortgrid lines 33 are connected with the conductive wires 32. Preferably,the short grid lines 33 and the metal wire at the front surface of thecell 31 are connected at a turn.

According to an embodiment of the present disclosure, the short gridlines 33 are perpendicular to the secondary grid lines 312. The shortgrid lines 33 are, preferably, electrically connected with bended parts(ends proximate to the edges) of the conductive wires 32 on the shinysurface of the cell 31. An extra welding point can be added to decreasethe probability of breaking the welding portion at the edges, and tofurther enhance the binding force of the metal wire and the cell. Theconnection with at the turn herein can be understood that the short gridlines 33 have intersection points with the turns, i.e. the short gridlines 33 do not terminate at the turns. More preferably, at least oneshort grid line 33 is disposed corresponding with each bended part. Ofcourse, the short gird lines 33 can be connected with other parts of theconductive wires 32, for example, arc segments.

Since the distance between the bended parts of the conductive wires 32and the edges of the cell 31 is usually short, the short grid lines 33have a length of 1 to 10 mm, preferably 2.4 to 7 mm, a width of 0.05 to0.5 mm, and a thickness of 0.01 to 0.02 mm. There are 3 to 40,preferably 6 to 20 short grid lines.

The short grid lines 33 can be disposed in the same manner as thesecondary grid lines 312 on the shiny surface of the cell 31. Forexample, the short grid lines 33 can be printed along with the secondarygrid lines 312 by silk-screen printing at the same screen plate (whichcan be made of silver paste) as the front secondary grid lines 3121.

In some preferable embodiments of the present disclosure, the secondarygrid lines 312 have a width of 40 to 80 μm and a thickness of 5 to 20μm; there are 50 to 120 secondary grid lines, a distance betweenadjacent secondary grid lines ranging from 0.5 to 3 mm.

Alternatively, the metal wire breaks off at a turn after being connectedwith the cell 31. The metal wire breaks off at the turn after beingwelded with the cell 31 to form multiple independent conductive wires32. The metal wire breaks off at the turn after being welded with thecell 31 to separate the multiple conductive wires 32, which can decreasethe stress between the cells and peeling strength at the joints of themetal wire and the cell, and further improve the photoelectricconversion efficiency of the solar cell array 30.

In some specific embodiments of the present disclosure, in a row of thecells 31, the adjacent cells are connected by a metal wire that extendsreciprocally between a surface of a first cell 31 and a surface of asecond cell 31 adjacent to the first cell and constitutes the conductivewire 32. Alternatively, a plurality of cells 31 are arranged in an n×mmatrix form, and in two adjacent rows of cells 31, the metal wireextends reciprocally between a surface of a cell 31 in a a^(th) row anda surface of a cell in a (a+1)^(th) row, in which n represents a column,m represents a row, and m−1≧a≧1.

Alternatively, in two adjacent rows of cells 31, the metal wire extendsreciprocally between a surface of a cell 31 at an end of the a^(th) rowand a surface of a cell 31 at an end of the (a+1)^(th) row, the end ofthe a^(th) row and the end of the (a+1)^(th) row located at the sameside of the matrix form.

Preferably, in the same row of cells 31, the metal wire extendsreciprocally between a front surface of a first cell 31 and a backsurface of a second cell 31 adjacent to the first cell 31. In twoadjacent rows of cells 31, the metal wire extends reciprocally between afront surface of a cell 31 at an end of the a^(th) row and a backsurface of a cell 31 at an end of the (a+1)^(th) row, to connect the twoadjacent rows of cells 31 in series.

In other words, the solar cell array 30 according to the embodiment ofthe present disclosure is arranged in an n×m matrix form by a pluralityof cells 31. Specifically, in the solar cell array 30, there aremultiple cells 31, and the cells are arranged in the n×m matrix form. Ina row of cells, the conductive wire 32 extends from a surface of a firstcell 31, and is electrically connected with a surface of a second cell31 adjacent to the first cell 31, to connect the cells 31 in the samerow; in two adjacent rows of cells, the conductive wire 32 extends froma surface of a cell 31 in a a^(th) row and is electrically connectedwith a surface of a cell in a (a+1)^(th) row, to connect the twoadjacent rows of cells 31, in which n represents a column, m representsa row, and m−1≧a≧1.

N can range from 2 to 30, m ranging from 2 to 18. Preferably, multiplecells 31 are arranged in a 12×6 or 10×6 matrix form, i.e. 10 or 12 cellsin a row, six rows in total. According to the preferable embodiment, thecells 31 in two adjacent rows are directly connected by the conductivewires without using the bus bars, which decreases the number of the busbars, shortens the connection distance, and reduces the resistance, soas to obtain higher electricity generation performance of the solar cellmodule.

Preferably, in the two adjacent rows of cells 31, the conductive wireextends from a surface of a cell 31 at an end of a a^(th) row and iselectrically connected with a surface of a cell at an end of a(a+1)^(th) row.

According to an embodiment of the present disclosure, the solar cellcomprises a plurality of cells 31, and the adjacent cells 31 areconnected by a plurality of conductive wires 32 constituted by a metalwire. At least one metal wire extends reciprocally between a surface ofa first cell 31 and a surface of a second cell 31 adjacent to the firstcell 31, and breaks off at a turn after being connected with the cells31.

That's to say, in the present application, the metal wire is welded withthe cell 31 after extending reciprocally between the surface of thefirst cell 31 and the surface of the second cell 31. It is evitable toform turns when the metal wire extends reciprocally between the surfaceof the first cell 31 and the surface of the second cell 31, and theturns are broken after the metal wire is welded with the cell 31.

Specifically, in the process of manufacturing the solar cell array 30,the turns of the metal wire are located beyond the edges of the cell 31;when the metal wire is welded with the cell 31, the whole cell 31 andthe corresponding metal wire can be held together by a pressing platefrom the upper and lower surfaces respectively.

If the turns of the metal wire are located within the edges of the cell31, two pressing plates are needed in each surface to press the wholecell 31 and the corresponding metal wire, so as to break the wire.Moreover, the cell 31 has to be pressed by the pressing plates beforeand after breaking the wire, i.e. two operations, which is complicatedto operate, and results in low efficiency.

In the present application, the metal wire is cut off at the turns, soas to reduce stress upon the metal wire at the turns and to guaranteethe welding effect.

It shall be explained that in the present disclosure, the two adjacentconductive wires form straight line segments parallel with each other,or line segments having arcs at ends.

That's to say, in the present disclosure, when the metal wire thatextends reciprocally between adjacent cells 31 breaks off at the turns,it can just simply break off at the turns, in which case the conductivewires 32 constituted by the metal wire will have arcs at the ends; thearc segments at the turns can be totally cut off, in which case theconductive wires 32 constituted by the metal wire will not have arcs atthe ends, and the adjacent conductive wires 32 are parallel with eachother.

Specifically, as shown in FIG. 13 and FIG. 14, the metal wire in FIG. 13extends reciprocally between two adjacent cells 31 to form a turn-backstructure, in which the metal wire is completely located within theedges of the cell 31; when the metal wire is cut off at the turns, thegaps 323 are at the ends of the turns of the metal wire. The structureof the metal wire after being cut off at the turns is shown in FIG. 14,and in this way the conductive wires 32 constituted by the metal wirewill have arcs at the ends.

In another embodiment of the present disclosure, as shown in FIG. 15 andFIG. 16, the metal wire in FIG. 15 extends reciprocally between twoadjacent cells 31 to form a turn-back structure, in which the turns ofthe metal wire are located beyond the edges of the cell 31; when themetal wire is cut off at the turns, the gaps 323 are located within thecell 31. In the process of cutting the metal wire, all the turns of themetal wire are completely cut off. In this way, the conductive wires 32constituted by the metal wire will not have arcs at the ends, and theadjacent conductive wires 32 are parallel with each other.

In addition, the conductive wires 32 is welded with the secondary gridlines 312 at the front surface of the cell 31 by a welding layer whichcoats the metal wire or is disposed on the secondary grid lines 312.

That's to say, the secondary grid lines 312 and the conductive wires 32are welded by a welding layer disposed on the secondary grid lines 312or coating the metal wire.

According to a preferable embodiment of the present disclosure, awelding layer is disposed at a position where the conductive wires 32are in contact with the secondary grid lines 312 and/or the backelectrodes 314 of the cell 31. More preferably, the welding layer isdisposed at the positions where the conductive wires 32 are in contactwith the secondary grid lines 312 of the cell 31 and in contact with theback electrodes 314 thereof respectively. The welding layer can be onlyapplied to the secondary grid lines 312 and back electrodes 314, or canalso be applied to the conductive wires 32. The welding layer may be ametal with a lower melting point or an alloy. The tin alloy can be aconventional tin alloy, for example, containing Sn, and at least one ofBi, Pb, Ag and Cu, more specifically, i.e. SnBi, SnPb, SnBiCu, SnPbAg,etc, so as to avoid insufficient soldering between the conductive wires32 and the secondary grid lines 312 and/or the back electrodes 314 ofthe cell, and to render the solar cell module higher photoelectricconversion efficiency.

In the cell array 30, the ratio of the thickness of the welding layerand the diameter of the metal wire is (0.02-0.5):1.

In the present disclosure, when there is a welding layer disposed at aposition where the conductive wires 32 are in contact with the secondarygrid lines 312 and/or the back electrodes 314 of the cell 31, theconductive wires 32 can be a metal wire. The metal wire may beconventional in the art, for example, a copper wire.

In an embodiment, the conductive wires (including the front conductivewires 32A and back conductive wires 32B) include a metal wire and analloy layer with a low melting point coating the metal wire. The alloylayer may coat the metal wire completely or partially. When the alloylayer coats the metal wire partially, the alloy layer is, preferably,formed at a position where the alloy layer is welded with the secondarygrid lines 312 and/or the back electrodes 314 of the cell 31. When thealloy layer coats the metal wire completely, the alloy layer can coatthe periphery of the metal wire in a circular manner. The thickness ofthe alloy layer can fall into a relatively wide range. Preferably, thealloy layer has a thickness of 1 to 100 μm, more preferably, 1 to 30 μm.The alloy for forming the alloy layer with a low melting point may be aconventional alloy with a low melting point which can be 100 to 200° C.Preferably, the alloy with the low melting point contains Sn, and atleast one of Bi, In, Ag, Sb, Pb and Zn, more preferably, containing Sn,Bi, and at least one of In, Ag, Sb, Pb and Zn. Specifically, the alloymay be at least one of Sn—Bi alloy, In—Sn alloy, Sn—Pb alloy, Sn—Bi—Pballoy, Sn—Bi—Ag alloy, In—Sn—Cu alloy, Sn—Bi—Cu alloy and Sn—Bi—Znalloy. Most preferably, the alloy is Bi—Sn—Pb alloy, for example,containing 40 weight percent of Sn, 55 weight percent of Bi, and 5weight percent of Pb (i.e. Sn40%-Bi55%-Pb5%). The thickness of the alloylayer with the low melting point can be 0.001 to 0.06 mm. The conductivewire 32 may have a cross section of 0.01 to 0.5 mm² The metal wire canbe conventional in the art, for example, a copper wire.

In the cell array 30, the cell 31 can be a conventional cell 31 in theart, for example, a polycrystalline silicon cell 31. The secondary gridlines 312 on the shiny surface of the cell 31 can be Ag, Cu, Sn, and tinalloy. The secondary grid line 312 has a width of 40 to 80 μm and athickness of 5 to 20 μm; there are 50 to 120 secondary grid lines, adistance between adjacent secondary grid lines ranging from 0.5 to 3 mm.The back electrodes 314 on the back surface of the cell 31 can be madeof Ag, Cu, Sn and tin alloys. The back electrodes 314 are usually in aribbon pattern, and have a width of 1 to 4 mm, and a thickness of 5 to20 μm.

The solar cell array 30 according to another embodiment of the presentdisclosure is illustrated with reference to FIG. 6.

The solar cell array 30 according to the embodiment of the presentdisclosure comprises n×m cells 31. In other words, a plurality of cells31 are arranged in an n×m matrix form, n representing a column, and mrepresenting a row. More specifically, in the embodiment, 36 cells 31are arranges into six columns and six rows, i.e. n=m=6. It can beunderstood that the present disclosure is not limited thereto. Forexample, the column number and the row number can be different. Forconvenience of description, in FIG. 6, in a direction from left toright, the cells 31 in one row are called a first cell 31, a second cell31, a third cell 31, a fourth cell 31, a fifth cell 31, and a sixth cell31 sequentially; in a direction from up to down, the columns of thecells 31 are called a first column of cells 31, a second column of cells31, a third column of cells 31, a fourth column of cells 31, a fifthcolumn of cells 31, and a sixth column of cells 31 sequentially.

In a row of the cells 31, the metal wire extends reciprocally between asurface of a first cell 31 and a surface of a second cell 31 adjacent tothe first cell 31; in two adjacent rows of cells 31, the metal wireextends reciprocally between a surface of a cell 31 in a a^(th) row anda surface of a cell 31 in a (a+1)^(th) row, and m−1≧a≧1.

As shown in FIG. 6, in a specific example, in a row of the cells 31, themetal wire extends reciprocally between a front surface of a first cell31 and a back surface of a second cell 31 adjacent to the first cell 31,so as to connect the cells 31 in one row in series. In two adjacent rowsof cells 31, the metal wire extends reciprocally between a front surfaceof a cell 31 at an end of the a^(th) row and a back surface of a cell 31at an end of the (a+1)^(th) row, to connect the two adjacent rows ofcells 31 in series.

More preferably, in the two adjacent rows of cells 31, the metal wireextends reciprocally between the surface of the cell 31 at an end of thea^(th) row and the surface of the cell 31 at an end of the (a+1)^(th)row, the end of the a^(th) row and the end of the (a+1)^(th) row locatedat the same side of the matrix form, as shown in FIG. 6, located at theright side thereof.

More specifically, in the embodiment as shown in FIG. 6, in the firstrow, a first metal wire extends reciprocally between a front surface ofa first cell 31 and a back surface of a second cell 31; a second metalwire extends reciprocally between a front surface of the second cell 31and a back surface of a third cell 31; a third metal wire extendsreciprocally between a front surface of the third cell 31 and a backsurface of a fourth cell 31; a fourth metal wire extends reciprocallybetween a front surface of the fourth cell 31 and a back surface of afifth cell 31; a fifth metal wire extends reciprocally between a frontsurface of the fifth cell 31 and a back surface of a sixth cell 31. Insuch a way, the adjacent cell bodies 31 in the first row are connectedin series by corresponding metal wires.

A sixth metal wire extends reciprocally between a front surface of thesixth cell 31 in the first row and a back surface of a sixth cell 31 inthe second row, such that the first row and the second row are connectedin series. A seventh metal wire extends reciprocally between a frontsurface of the sixth cell 31 in the second row and a back surface of afifth cell 31 in the second row; a eighth metal wire extendsreciprocally between a front surface of the fifth cell 31 in the secondrow and a back surface of a fourth cell 31 in the second row, until aeleventh metal wire extends reciprocally between a front surface of asecond cell 31 in the second row and a back surface of a first cell 31in the second row, and then a twelfth metal wire extends reciprocallybetween a front surface of the first cell 31 in the second row and aback surface of a first cell 31 in the third row, such that the secondrow and the third row are connected in series. Sequentially, the thirdrow and the fourth row are connected in series, the fourth row and thefifth row connected in series, the fifth row and the sixth row connectedin series, such that the cell array 30 is manufactured. In thisembodiment, a bus bar is disposed at the left side of the first cell 31in the first row and the left side of the first cell 31 in the sixth rowrespectively; a first bus bar is connected with the conductive wiresextending from the left side of the first cell 31 in the first row, anda second bus bar is connected with the conductive wires extending fromthe left side of the first cell 31 in the sixth row.

As said above, the cell bodies in the embodiments of the presentdisclosure are connected in series by the conductive wires—the firstrow, the second row, the third row, the fourth row, the fifth row andthe sixth row are connected in series by the conductive wires. As shownin the figures, the metal wire may extend beyond the cell for connectionwith other loads. For example, alternatively, the second and third row,and the fourth and fifth rows can be connected in parallel with a dioderespectively to avoid light spot effect. The diode can be connected in amanner commonly known to those skilled in the art, for example, by a busbar.

However, the present disclosure is not limited to the above. Forexample, the first and second rows can be connected in series, the thirdand fourth rows connected in series, the fifth and sixth rows connectedin series, and meanwhile the second and third rows are connected inparallel, the fourth and fifth connected in parallel. In such a case, abus bar can be disposed at the left or right side of corresponding rowsrespectively.

Alternatively, the cells 31 in the same row can be connected inparallel. For example, a metal wire extends reciprocally from a frontsurface of a first cell 31 in a first row through the front surfaces ofthe second to the sixth cells 31.

In some specific embodiments of the present disclosure, a binding forcebetween the metal wire and the cells 31 ranges from 0.1 N to 0.8 N.That's to say, the binding force between the conductive wires 32 and thecells 31 ranges from 0.1 N to 0.8 N. Preferably, the binding forcebetween the metal wire and the cells ranges from 0.2 N to 0.6 N, so asto secure the welding between the cells and the metal wire, to avoidsealing-off of the cells in the operation and the transferring processand performance degradation due to poor connection, and to lower thecost.

The solar cell module 100 according to embodiments of the presentdisclosure is illustrated with reference to FIG. 10 and FIG. 11.

As shown in FIG. 10 and FIG. 11, the solar cell module 100 according toembodiments of the present disclosure includes an upper cover plate 10,a front adhesive layer 20, the cell array 30, a back adhesive layer 40and a back plate 50 superposed sequentially along a direction from up todown.

The front adhesive layer 20 and the back adhesive layer 40 are adhesivelayers commonly used in the art. Preferably, the front adhesive layer 20and the back adhesive layer 40 are polyethylene-octene elastomer (POE)and/or ethylene-vinyl acetate copolymer (EVA). In the presentdisclosure, polyethylene-octene elastomer (POE) and/or ethylene-vinylacetate copolymer (EVA) are conventional products in the art, or can beobtained in a method known to those skilled in the art.

In the embodiments of the present disclosure, the upper cover plate 10and the back plate 50 can be selected and determined by conventionaltechnical means in the art. Preferably, the upper cover plate 10 and theback plate 50 can be transparent plates respectively, for example, glassplates.

In the process of manufacturing the solar cell module 100, theconductive wire can be first bounded or welded with the secondary gridlines and the back electrode of the cell 31, and then superposed andlaminated.

Other components of the solar cell module 100 according to the presentdisclosure are known in the art, which will be not described in detailherein.

Specifically, the solar module 100 includes an upper cover plate 10, afront adhesive layer 20, the cell array 30, a back adhesive layer 40 anda back plate 50. The cell array 30 includes a plurality of cells 31, andadjacent cells 31 are connected by the plurality of conductive wires 32.At least two conductive wires 32 are constituted by the metal wire Swhich extends reciprocally between surfaces of adjacent cells. Theconductive wires 32 are welded with the secondary grid lines. The frontadhesive layer 20 contacts with the conductive wires 32 directly andfills between the adjacent conductive wires 32.

That's to say, the solar cell module 100 according to the presentdisclosure includes an upper cover plate 10, a front adhesive layer 20,the cell array 30, a back adhesive layer 40 and a back plate 50superposed sequentially along a direction from up to down. The cellarray 30 includes a plurality of cells 31 and conductive wires 32 forconnecting the plurality of cells 31. The conductive wires areconstituted by the metal wire S which extends reciprocally betweensurfaces of two adjacent cells 31.

The conductive wires 32 are electrically connected with the cells 31, inwhich the front adhesive layer 20 on the cells 31 contacts with theconductive wires 32 directly and fills between the adjacent conductivewires 32, such that the front adhesive layer 20 can fix the conductivewires 32, and separate the conductive wires 32 from air and moisturefrom the outside world, so as to prevent the conductive wires 32 fromoxidation and to guarantee the photoelectric conversion efficiency.

Thus, in the solar cell module 100 according to embodiments of thepresent disclosure, the conductive wires 32 constituted by the metalwire S which extends reciprocally replace traditional primary grid linesand solder strips, so as to reduce the cost. The metal wire S extendsreciprocally to decrease the number of free ends of the metal wire S andto save the space for arranging the metal wire S, i.e. without beinglimited by the space. The number of the conductive wires 32 constitutedby the metal wire which extends reciprocally may be increasedconsiderably, which is easy to manufacture, and thus is suitable formass production. The front adhesive layer 20 contacts with theconductive wires 32 directly and fills between the adjacent conductivewires 32, which can effectively isolate the conductive wires from airand moisture to prevent the conductive wires 32 from oxidation toguarantee the photoelectric conversion efficiency.

In some specific embodiments of the present disclosure, the metal wire Sextends reciprocally between a front surface of a first cell and a backsurface of a second cell adjacent to the first cell; the front adhesivelayer 20 contacts with the conductive wires on the front surface of thefirst cell 31 directly and fills between the adjacent conductive wires32 on the front surface of the first cell 31; the back adhesive layer 40contacts with the conductive wires 32 on the back surface of the secondcell 31 directly and fills between the adjacent conductive wires 32 onthe back surface of the second cell 31.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has aseries resistance of 380 to 440 mΩ per 60 cells. The present disclosureis not limited to 60 cells, and there may be 30 cells, 72 cells, etc.When there are 72 cells, the series resistance of the solar cell moduleis 456 to 528 mΩ, and the electrical performance of the cells is better.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has anopen-circuit voltage of 37.5-38.5 V per 60 cells. The present disclosureis not limited to 60 cells, and there may be 30 cells, 72 cells, etc.The short-circuit current is 8.9 to 9.4 A, and is not related to thenumber of the cells.

In some specific embodiments of the present disclosure, the solar cellmodule has a fill factor of 0.79 to 0.82, which is independent from thedimension and number of the cells, and can affect the electricalperformance of the cells.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has aworking voltage of 31.5-32 V per 60 cells. The present disclosure is notlimited to 60 cells, and there may be 30 cells, 72 cells, etc. Theworking current is 8.4 to 8.6 A, and is not related to the number of thecells.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has aconversion efficiency of 16.5-17.4%, and a power of 265-280 W per 60cells.

A method for manufacturing the solar cell module 100 according to theembodiments of the present disclosure will be illustrated with respectto FIG. 1 to FIG. 3 and FIG. 7 to FIG. 9.

The method includes: arranging a plurality of cells 31 into a cell array30 of multiple rows and multiple columns; forming a plurality ofconductive wires 32 by a metal wire which extends reciprocally between asurface of a cell 31 in a row and a surface of a cell 31 in another row,to connect the cells in different rows by the conductive wires 32;superposing an upper cover plate 10, a front adhesive layer 20, the cellarray 30, a back adhesive layer 40 and a back plate 50 in sequence, inwhich a front surface of the cell 31 faces the front adhesive layer 20,such that the front adhesive layer 20 contacts with the conductive wires32 directly; and a back surface of the cell 31 faces the back adhesivelayer 40, and laminating them, in which the front adhesive layer 20fills between adjacent conductive wires 32, so as to obtain the solarcell module 100.

In other words, in the process of manufacturing the solar cell module100, the plurality of cells 31 are arranged into the cell array 30 ofmultiple rows and multiple columns. The metal wire S extendsreciprocally between surfaces of the adjacent cells in the same row andcontacts with the surfaces of the cells to constitute the conductivewires 32 in the same row. Then the metal wire S extends reciprocallybetween a surface of a cell 31 in a row and a surface of a cell 31 inanother row to constitute multiple conductive wires 32 in the samecolumn.

Then, the upper cover plate 10, the front adhesive layer 20, the cellarray 30, the back adhesive layer 40 and the back plate 50 aresuperposed in sequence, in which the front adhesive layer 20 contactswith the conductive wires 32 directly. Finally, the upper cover plate10, the front adhesive layer 20, the cell array 30, the back adhesivelayer 40 and the back plate 50 are laminated, in which the frontadhesive layer 20 fills between adjacent conductive wires 32, so asobtain the solar cell module 100 said above.

Specifically, as shown in FIG. 7, the metal wire extends reciprocallyfor 12 times under a strain. As shown in FIG. 8, a first cell 31A and asecond cell 31B are prepared. As shown in FIG. 9, a front surface of thefirst cell 31A is connected with a metal wire, and a back surface of thesecond cell 31B is connected with the metal wire, so as to form a cellarray 30. FIG. 9 shows two cells 31. As above, when the cell array 30has a plurality of cells 31, the metal wire extends reciprocally toconnect the front surface of the first cell 31 and the back surface ofthe second cell 31 adjacent to the first cell 31, i.e. connectingsecondary grid lines of the first cell 31 with back electrodes of thesecond cell 31 by the metal wire. The metal wire extends reciprocallyunder a strain from two clips at two ends thereof. The metal wire can bewinded only with the help of two clips, which saves the clipsconsiderably and then reduces the assembling space.

In the embodiment shown in FIG. 9, the adjacent cells are connected inseries. As above, the adjacent cells can be connected in parallel by themetal wire in the light of practical requirements.

The cell array 30 obtained is superposed with the upper cover plate 10,the front adhesive layer 20, the back adhesive layer 40 and the backplate 50 in sequence, in which the front surfaces of the cells 31 facethe front adhesive layer 20, and the back surfaces thereof face the backadhesive layer 40, and then they are laminated to obtain the solar cellmodule 100. It can be understood that the metal wire can be bound orwelded with the cells 31, and the connection of the metal wire and thecells 31 can be conducted in the laminating process. Of course, they canbe first connected and then laminated.

A method for manufacturing the solar cell module 100 according toanother embodiment of the present disclosure will be illustrated withrespect to FIG. 1 to FIG. 3 and FIG. 7 to FIG. 9.

Specifically, the method according to the embodiments of the presentdisclosure includes the following steps:

forming a plurality of conductive wires 32 by a metal wire which extendsreciprocally a surface of a first cell 31 of a plurality of cells 31 anda surface of a second cell 31 thereof, such that the adjacent cells 31are connected by the plurality of conductive wires 32 to constitute acell array 30, wherein the plurality of cells 31 are arranged in an n×mmatrix form; in a row of cells 31, a metal wire extends reciprocallybetween a surface of a first cell 31 and a surface of a second cell 31adjacent to the first cell 31; in two adjacent rows of cells 31, themetal wire extends reciprocally between a surface of a cell 31 in aa^(th) row and a surface of a cell 31 in a (a+1)^(th) row to obtain thecell array 30, n representing a column, m representing a row andm−1≧a≧1, a secondary grid line 312 and a short grid line 33 beingdisposed on a front surface of the cell 31, the secondary grid line 312including a middle secondary grid line 3122 intersected with theconductive wire 32 and an edge secondary grid line 3121 non-intersectedwith the conductive wire 32, the short grid line 33 being connected withthe edge secondary grid line 3121, and being connected with theconductive wire 32 or at least one middle secondary grid line 3122, themetal wire being coated with a welding layer by which the metal wire iswelded with the middle secondary grid line 3122;

superposing the upper cover plate 10, the front adhesive layer 20, thecell array 30, the back adhesive layer 40 and the back plate 50 insequence, in which the front surface of the cell 31 faces the frontadhesive layer 20, and the back surface thereof faces the back adhesivelayer 40, and laminating them to obtain the solar cell module 100.

Specifically, the short grid lines 33 can be manufactured in the sameway as the secondary grid lines 312 on the shiny surface of the cell 31,for example, screen printed in conjunction with the secondary grid linesand with the help of the same screen printing plate as the frontsecondary gird lines 3121, and the short grid lines 33 may be made ofsilver paste.

The method includes the steps of preparing a solar array 30, superposingthe upper cover plate 10, the front adhesive layer 20, the cell array30, the back adhesive layer 40 and the back plate 50 in sequence, andlaminating them to obtain the solar cell module 100. It can beunderstood that the method further includes other steps, for example,sealing the gap between the upper cover plate 10 and the back plate 50by a sealant, and fixing the above components together by a U-shapeframe, which are known to those skilled in the art, and thus will be notdescribed in detail herein.

The method includes a step of forming a plurality of conductive wires bya metal wire which extends reciprocally on surfaces of cells 31 and iselectrically connected with the surfaces of cells 31, such that theadjacent cells 31 are connected by the plurality of conductive wires toconstitute a cell array 30.

Specifically, as shown in FIG. 7, the metal wire extends reciprocallyfor 12 times under a strain. As shown in FIG. 8, a first cell 31 and asecond cell 31 are prepared. As shown in FIG. 9, a front surface of thefirst cell 31 is connected with a metal wire, and a back surface of thesecond cell 31 is connected with the metal wire, such that the cellarray 30 is formed. FIG. 9 shows two cells 31. When the cell array 30has a plurality of cells 31, the metal wire which extends reciprocallyconnects the front surface of the first cell 31 and the back surface ofthe second cell 31 adjacent to the first cell 31, i.e. connecting asecondary grid line of the first cell 31 with a back electrode of thesecond cell 31 by the metal wire. The metal wire extends reciprocallyunder a strain from two clips at two ends thereof. The metal wire can bewinded only with the help of two clips, which saves the clipsconsiderably and then reduces the assembling space.

In the embodiment shown in FIG. 9, the adjacent cells are connected inseries. As said above, the adjacent cells can be connected in parallelby the metal wire based on practical requirements.

The cell array 30 obtained is superposed with the upper cover plate 10,the front adhesive layer 20, the back adhesive layer 40 and the backplate 50 in sequence, in which a front surface of the cell 31 faces thefront adhesive layer 20, a back surface thereof facing the back adhesivelayer 40, and laminating them to obtain the solar cell module 100. Itcan be understood that the metal wire can be bounded or welded with thecell 31 when or before they are laminated.

The front adhesive layer 20 is disposed in direct contact with theconductive wires 32. In the process of laminating, the front adhesivelayer 20 melts and fills the gaps between adjacent conductive wires 32.The back adhesive layer 40 is disposed in direct contact with theconductive wires 32. In the process of laminating, the back adhesivelayer 40 melts and fills the gaps between adjacent conductive wires 32.

A method for manufacturing the solar cell module 100 according to theembodiments of the present application will be illustrated with respectto FIG. 7 to FIG. 9, and FIG. 15 to FIG. 18.

The method according to the embodiments of the present inventionincludes the following steps: forming at least two conductive wires by ametal wire which extends reciprocally between a surface of a first celland a surface of a second cell adjacent to the first cell, welding themetal wire with secondary grid lines on the front surface of the cell,such that adjacent cells are connected by the plurality of conductivewires; breaking the metal wire at turns thereof to obtain a cell array30; superposing the upper cover plate 10, the front adhesive layer 20,the cell array 30, the back adhesive layer 40 and the back plate 50 insequence, in which the front surface of the cell 31 faces the frontadhesive layer 20, and the back surface thereof faces the back adhesivelayer 40, and laminating them to obtain the solar cell module 100.

The method includes the steps of preparing a solar array 30, superposingthe upper cover plate 10, the front adhesive layer 20, the cell array30, the back adhesive layer 40 and the back plate 50 in sequence, andlaminating them to obtain the solar cell module 100. It can beunderstood that the method further includes other steps, for example,sealing the gap between the upper cover plate 10 and the back plate 50by a sealant, and fixing the above components together by a U-shapeframe, which are known to those skilled in the art, and thus will be notdescribed in detail herein.

The method includes a step of forming a plurality of conductive wires bya metal wire which extends reciprocally surfaces of cells 31 and iselectrically connected with the surfaces of cells 31, such that theadjacent cells 31 are connected by the plurality of conductive wires toconstitute a cell array 30.

Specifically, as shown in FIG. 7, the metal wire extends reciprocallyfor 12 times under a strain. As shown in FIG. 8, a first cell 31 and asecond cell 31 are prepared. As shown in FIG. 9, a front surface of thefirst cell 31 is connected with a metal wire, and a back surface of thesecond cell 31 is connected with the metal wire, such that the cellarray 30 is formed. FIG. 9 shows two cells 31. When the cell array 30has a plurality of cells 31, the metal wire which extends reciprocallyconnects the front surface of the first cell 31 and the back surface ofthe second cell 31 adjacent to the first cell 31, i.e. connecting asecondary grid line of the first cell 31 with a back electrode of thesecond cell 31 by the metal wire. The metal wire extends reciprocallyunder a strain from two clips at two ends thereof. The metal wire can bewinded only with the help of two clips, which saves the clipsconsiderably and then reduces the assembling space.

In the embodiment shown in FIG. 9, the adjacent cells are connected inseries. As said above, the adjacent cells can be connected in parallelby the metal wire based on practical requirements.

The metal wire is welded with the cell 31 under a strain, and afterwelding, the metal wire is cut off at the turns. In such a way, adjacentcells are connected into a cell array 30.

The cell array 30 obtained is superposed with the upper cover plate 10,the front adhesive layer 20, the back adhesive layer 40 and the backplate 50 in sequence, in which a front surface of the cell 31 faces thefront adhesive layer 20, a back surface thereof facing the back adhesivelayer 40, and laminating them to obtain the solar cell module 100. Itcan be understood that the metal wire can be connected with the cell 31when or before they are laminated.

The front adhesive layer 20 is disposed in direct contact with theconductive wires 32. In the process of laminating, the front adhesivelayer 20 melts and fills the gaps between adjacent conductive wires 32.The back adhesive layer 40 is disposed in direct contact with theconductive wires 32. In the process of laminating, the back adhesivelayer 40 melts and fills the gaps between adjacent conductive wires 32.

In the following, the solar cell module 100 of the present disclosurewill be described with respect to specific examples.

Example 1

Example 1 is used to illustrate the solar cell module 100 according tothe present disclosure and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.04 mm², and the alloy layer has a thickness of 16 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module 100

A POE adhesive layer in 1630×980×0.5 mm is provided (melting point: 65°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm width, 9 μm in thickness), eachof which substantially runs through the cell 31 in a longitudinaldirection, and the distance between the adjacent secondary grid lines is1.7 mm. The cell 31 has five back electrodes (tin, 1.5 mm in width, 10μm in thickness) on its back surface. Each back electrode substantiallyruns through the cell 31 in a longitudinal direction, and the distancebetween the adjacent back electrodes is 31 mm.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under strain. The metal wire extends reciprocally understrain from two clips at two ends thereof, so as to form 15 parallelconductive wires. The secondary grid lines of the first cell 31 arewelded with the conductive wires and the back electrodes of the secondcell 31 are welded with the conductive wires at a welding temperature of160° C. The distance between parallel adjacent conductive wires is 9.9mm. 10 cells are connected in series into a row, and six rows of thecells of such kind are connected in series into a cell array via the busbar. Then, an upper glass plate, an upper POE adhesive layer, multiplecells arranged in a matrix form and welded with the metal wire, a lowerPOE adhesive layer and a lower glass plate are superposed sequentiallyfrom up to down, in which the front surface of the cell 31 faces thefront adhesive layer 20, such that the front adhesive layer 20 contactswith the conductive wires 32 directly; and the back surface of the cell31 faces the back adhesive layer 40, and finally they are laminated in alaminator, in which the front adhesive layer 20 fills between adjacentconductive wires 32. In such way, a solar cell module A1 is obtained.

Comparison Example 1

The difference between Comparison example 1 and Example 1 lies in thatthe cells 31 are arranged in a matrix form, and in two adjacent cells,the fifteen parallel metal wires, by wiredrawing as shown in FIG. 13,are strained via the clips 34 at the ends of each metal wire, and thusthe cells are flattened at a strain of 2 N of the clips. Each of thefifteen parallel metal wires is welded with secondary grid lines on afront surface of a first cell 31 respectively, and welded with backelectrodes on a back surface of a second cell 31. The distance betweenthe parallel adjacent conductive wires is 9.9 mm (as shown in FIG. 13).In such a way, a solar cell module D1 is obtained.

Comparison Example 2

The differences between Comparison example 2 and Comparison example 1lie in that the cells are arranged in a matrix form; 15 metal wiresconnected in series are pasted at a transparent adhesive layer, and themetal wires are attached to the solar cells. In two adjacent cells, themetal wire connects a front surface of a first cell and a back surfaceof a second cell. Then, an upper glass plate, an upper POE adhesivelayer, and a first transparent adhesive layer, multiple cells arrangedin a matrix form and welded with the metal wire, a second transparentadhesive layer, a lower POE adhesive layer and a lower glass plate aresuperposed sequentially from up to down. Thus, a solar cell module D2 isobtained.

Example 2

Example 2 is used to illustrate the solar cell module 100 according tothe present disclosure and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.03 mm², and the alloy layer has a thickness of 10 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module

A EVA adhesive layer in 1630×980×0.5 mm is provided (melting point: 60°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness) atits shiny surface, each of which substantially runs through the cell 31in a longitudinal direction, and the distance between the two adjacentsecondary grid lines is 1.7 mm. The cell 31 has five back electrodes(tin, 1.5 mm in width, 10 μm) in thickness) on its back surface. Eachback electrode substantially runs through the cell 31 in thelongitudinal direction, and the distance between the two adjacent backelectrodes is 31 mm.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under strain. The metal wire extends reciprocally understrain from two clips at two ends thereof, so as to form 20 parallelconductive wires. The secondary grid lines of the first cell 31 arewelded with the conductive wires and the back electrodes of the secondcell 31 are welded with the conductive wires at a welding temperature of160° C. The distance between parallel adjacent conductive wires is 7 mm.10 cells are connected in series into a row, and six rows of the cellsof such kind are connected in series into a cell array via the bus bar.Then, an upper glass plate, an upper POE adhesive layer, multiple cellsarranged in a matrix form and welded with the metal wire, a lower POEadhesive layer and a lower glass plate are superposed sequentially fromup to down, in which the front surface of the cell 31 faces the frontadhesive layer 20, such that the front adhesive layer 20 contacts withthe conductive wires 32 directly; and the back surface of the cell 31faces the back adhesive layer 40, and finally they are laminated in alaminator, in which the front adhesive layer 20 fills between adjacentconductive wires 32. In such way, a solar cell module A2 is obtained.

Example 3

The solar cell module is manufactured according to the method in Example2, but the difference compared with Example 2 lies in that short gridlines 33 (silver, 0.1 mm in width) are disposed on the secondary gridlines of the front surface of the cell 31, and are perpendicular to thesecondary grid lines for connecting part of the secondary grid lines atthe edges of the front surface of the cell with the conductive wires. Asshown in FIG. 12, a solar cell module A3 is obtained.

Example 4

The solar cell module is manufactured according to the method in Example3, but the difference compared with Example 3 lies in that the cellarray is connected in such a manner that in two adjacent rows of cells,the conductive wires extend from a shiny surface of a cell at an end ofthe a^(th) row (a≧1) to form electrical connection with a back surfaceof a cell 31 at an adjacent end of the (a+1)^(th) row, so as to connectthe two adjacent rows of cells. The conductive wires for connecting thetwo adjacent rows of cells 31 are arranged in perpendicular to theconductive wires for connecting the adjacent cells 31 in the two rows.In such a way, a solar cell module A4 is obtained.

Testing Example 1

(1) Whether the metal wire in the solar cell module drifts is observedwith the naked eyes;

(2) According to the method disclosed in IEC904-1, the solar cellmodules manufactured in the above examples and the comparison exampleare tested with a single flash simulator under standard test conditions(STC): 1000 W/m² of light intensity, AM1.5 spectrum, and 25° C. Thephotoelectric conversion efficiency of each cell is recorded. Thetesting result is shown in Table 1.

TABLE 1 Solar cell module A1 D1 D2 A2 A3 A4 Metal wire no Slightly no nono no drifting phenomenon Photoelectric 16.5% 15.6% 15.7% 16.7% 17.0%17.2% conversion efficiency Series 458 493 482 445 433 429 resistance(mΩ) Fill factor 0.779 0.759 0.756 0.783 0.790 0.794 Open-circuit 37.6537.54 37.63 37.75 37.86 37.88 voltage (V) Short-circuit 9.048 8.8028.879 9.085 9.143 9.198 current (A) Working 31.15 30.38 30.44 31.3431.76 31.97 voltage (V) Working 8.520 8.26 8.296 8.571 8.610 8.651current (A) Power (W) 265.4 250.9 252.5 268.6 273.4 276.6

The fill factor refers to a ratio of the power at the maximum powerpoint of the solar cell module and the maximum power theoretically atzero resistance, and represents the proximity of the actual power withrespect to the theoretic maximum power, in which the greater the valueis, the higher the photoelectric conversion efficiency is. Generally,the series resistance is small, so the fill factor is great. Thephotoelectric conversion efficiency refers to a ratio of converting theoptical energy into electric energy by the module under a standardlighting condition (1000 W/m² of light intensity). The series resistanceis equivalent to the internal resistance of the solar module, in whichthe greater the value is, the poorer the performance of the module is.The fill factor represents a ratio of the actual maximum power and thetheoretical maximum power of the module, in which the greater the valueis, the better the performance of the module is. The open-circuitvoltage refers to the voltage of the module in an open circuit under astandard lighting condition. The short-circuit current refers to thecurrent of the module in a short circuit under a standard lightingcondition. The working voltage is the output voltage of the moduleworking with the largest power under a standard lighting condition. Theworking current is the output current of the module working with thelargest power under a standard lighting condition. The power is themaximum power which the module can reach under a standard lightingcondition.

It can be indicated from Table 1 that for the solar cell moduleaccording to the embodiments of the present disclosure, the metal wirewill not drift, and higher photoelectric conversion efficiency can beobtained.

Testing Example 2

(1) Welding a metal wire onto a surface of a cell, the metal wire beingin perpendicular to secondary grid lines of the cell;

(2) Placing the cell horizontally at a testing position of a tensiletester, and pressing blocks on the cell, in which the pressing blocksare disposed at two sides of the metal wire, such that the cell will notbe pulled up during the test;

(3) Clamping the metal wire at a pull ring of a tension meter that formsan angle of 45° with the cell;

(4) Actuating the tension meter, such that the tension meter movesuniformly along a vertical direction, pulls up the metal wire from thesurface of the cell and records the pull data tested, in which the datais averaged to obtain the pull data of the metal wire. The testingresult is shown in Table 2.

TABLE 2 Module A1 D1 D2 A2 A3 A4 Tensile force (N) 0.45 0.38 0.25 0.260.34 0.33

It can be indicated from Table 2 that for the solar cell moduleaccording to the embodiments of the present disclosure, greater tensileforce is needed to pull the metal wire away from the upper gall of thecell, which proves stronger stability of connection between the metalwire and the cell in the solar cell module.

Example 21

Example 21 is used to illustrate the solar cell module 100 according tothe present disclosure and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.04 mm², and the alloy layer has a thickness of 16 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module 100

A POE adhesive layer in 1630×980×0.5 mm is provided (melting point: 65°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness) onits front surface, each of which substantially runs through the cell 31in a longitudinal direction, and the distance between the adjacentsecondary grid lines is 1.7 mm.

The short grid lines are printed at an edge of a side of the frontsurface of the cell by a newly designed secondary grid mesh at the sametime of printing the secondary grid lines. The short grid lines areperpendicular to the secondary grid lines, and connected with theoutermost secondary grid line at the edge. The short grid line printedhas a length of 5.1 mm and a width of 0.2 mm. There are eight short gridlines.

The cell 31 has five back electrodes (tin, 1.5 mm in width, 10 μm inthickness) on its back surface. Each back electrode substantially runsthrough the cell 31 in a longitudinal direction, and the distancebetween the adjacent back electrodes is 31 mm.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under strain. The metal wire extends reciprocally understrain from two clips at two ends thereof, and is intersected with theshort gird lines at the turns formed by reciprocal extension, so as toform 15 parallel conductive wires. The secondary grid lines of the firstcell 31 are welded with the conductive wires and the back electrodes ofthe second cell 31 are welded with the conductive wires. The distancebetween parallel adjacent conductive wires is 9.9 mm. 10 cells areconnected in series into a row, and identical metal wires are arrangedin the above way to obtain the same conductive wires, such that six rowsof the cells of such kind are connected in series into a cell array.Then, an upper glass plate, an upper POE adhesive layer, multiple cellsarranged in a matrix form and welded with the metal wire, a lower POEadhesive layer and a lower glass plate are superposed sequentially fromup to down, in which the front surface of the cell 31 faces the frontadhesive layer 20, such that the front adhesive layer 20 contacts withthe conductive wires 32 directly; and the back surface of the cell 31faces the back adhesive layer 40, and finally they are laminated in alaminator, in which the front adhesive layer 20 fills between adjacentconductive wires 32. In such way, a solar cell module A21 is obtained.

Comparison Example 21

The difference of Comparison example 21 and Example 21 lies in that aconventional grid mesh is employed, and the short grid lines are notprinted at the same time of printing the secondary grid lines. In such away, a solar cell module D21 as shown in FIG. 12 is obtained.

Comparison Example 22

The differences between Comparison example 22 and Comparison example 21lie in that the cells are arranged in a matrix form; 15 metal wiresconnected in series are pasted at a transparent adhesive layer, and themetal wires are attached to the solar cells. In two adjacent cells, themetal wire connects a front surface of a first cell and a back surfaceof a second cell. Then, an upper glass plate, an upper POE adhesivelayer, and a first transparent adhesive layer, multiple cells arrangedin a matrix form and welded with the metal wire, a second transparentadhesive layer, a lower POE adhesive layer and a lower glass plate aresuperposed sequentially from up to down. Thus, a solar cell module D22is obtained.

Comparison Example 23

The difference of Comparison example 23 and Example 21 lies in that thecells 31 are arranged in a matrix form, and in two adjacent cells 31,each of the fifteen parallel metal wires, by wiredrawing as shown inFIG. 13, is strained by the clips 34 at the ends thereof to flatten thecell. the strain from the clips is 2N, such that each of the fifteenparallel metal wires is welded with a secondary grid line on a frontsurface of a first cell 31 respectively, and welded with a backelectrode on a back surface of a second cell 31. The distance between ofthe adjacent conductive wires 32C in parallel to each other is 9.9 mm.In such a way, a solar cell module D23 is obtained.

Example 22

Example 22 is used to illustrate the solar cell module 100 according tothe present disclosure and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.03 mm², and the alloy layer has a thickness of 10 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module

A EVA adhesive layer in 1630×980×0.5 mm is provided (melting point: 60°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness) atits shiny surface, each of which substantially runs through the cell 31in a longitudinal direction, and the distance between the two adjacentsecondary grid lines is 1.7 mm. The cell 31 has five back electrodes(tin, 1.5 mm in width, 10 μm in thickness) on its back surface. Eachback electrode substantially runs through the cell 31 in thelongitudinal direction, and the distance between the two adjacent backelectrodes is 31 mm.

The short grid lines are printed at an edge of a side of the frontsurface of the cell by a newly designed secondary grid mesh at the sametime of printing the secondary grid lines. The short grid lines areperpendicular to the secondary grid lines, and connected with theoutermost secondary grid line at the edge. The short grid line printedhas a length of 3.4 mm and a width of 0.1 mm. There are ten short gridlines.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under strain. The metal wire extends reciprocally understrain from two clips at two ends thereof, and is intersected with theshort gird lines at the turns formed by reciprocal extension, so as toform 20 parallel conductive wires. The secondary grid lines of the firstcell 31 are welded with the conductive wires and the back electrodes ofthe second cell 31 are welded with the conductive wires. The distancebetween parallel adjacent conductive wires is 7 mm. 10 cells areconnected in series into a row, and identical metal wires are arrangedin the above way to obtain the same conductive wires, such that six rowsof the cells of such kind are connected in series into a cell array.Then, an upper glass plate, an upper POE adhesive layer, multiple cellsarranged in a matrix form and welded with the metal wire, a lower POEadhesive layer and a lower glass plate are superposed sequentially fromup to down, in which the front surface of the cell 31 faces the frontadhesive layer 20, such that the front adhesive layer 20 contacts withthe conductive wires 32 directly; and the back surface of the cell 31faces the back adhesive layer 40, and finally they are laminated in alaminator, in which the front adhesive layer 20 fills between adjacentconductive wires 32. In such way, a solar cell module A22 is obtained.

Example 23

The solar cell module is manufactured according to the method in Example22, but the difference compared with Example 22 lies in that the shortgrid lines are printed at an edge of a side of the front surface of thecell by a newly designed secondary grid mesh at the same time ofprinting the secondary grid lines. The short grid lines areperpendicular to the secondary grid lines, and connected with theoutermost secondary grid line at the edge. The short grid line printedhas a length of 5.1 mm and a width of 0.15 mm. There are ten short gridlines. The turn formed by reciprocal extension is located between thesecond and the third short grid lines. The short grid lines areintersected with the third secondary grid line.

Example 24

The solar cell module is manufactured according to the method in Example22, but the difference compared with Example 22 lies in that after beingwelded the secondary grid lines, the metal wire cuts the arc segments atthe turns to form separate and parallel 20 metal wires. The distancebetween adjacent parallel primary grid lines is 7 mm. In such a way, asolar cell module A24 is obtained.

Example 25

The solar cell module is manufactured according to the method in Example21, but the difference compared with Example 1 lies in that the alloylayer is 50% Sn-48% Bi-1.5% Ag-0.5% Cu (melting point: 160° C.). In sucha way, a solar cell module A25 is obtained.

Example 26

The solar cell module is manufactured according to the method in Example21, but the difference compared with Example 1 lies in that the alloylayer is 58% Bi-42% Sn. In such a way, a solar cell module A26 isobtained.

Example 27

The solar cell module is manufactured according to the method in Example21, but the difference compared with Example 1 lies in that the alloylayer is 65% Sn-20% Bi-10% Pb-5% Zn. In such a way, a solar cell moduleA27 is obtained.

Testing Example 21

(1) Whether the metal wire in the solar cell module drifts is observedwith the naked eyes;

(2) According to the method disclosed in IEC904-1, the solar cellmodules manufactured in the above examples and the comparison exampleare tested with a single flash simulator under standard test conditions(STC): 1000 W/m² of light intensity, AM1.5 spectrum, and 25° C. Thephotoelectric conversion efficiency of each cell is recorded. Thetesting result is shown in Table 3.

TABLE 3 Solar cell module A21 D21 D22 D23 A22 A23 A24 A25 A26 A27 Metalwire no Slightly no Slightly no no no no no no drifting phenomenonPhotoelectric 17.30% 15.50% 15.30% 15.6% 17.10% 17.05% 17.20% 16.70%17.00% 16.80% conversion efficiency Series 425 498 515 493 442 445 427445 433 448 resistance (mΩ) Fill factor 0.796 0.764 0.742 0.759 0.7880.79 0.793 0.783 0.79 0.781 Open-circuit 37.94 37.44 37.52 37.54 37.8537.71 37.9 37.75 37.86 37.81 voltage (V) Short-circuit 9.212 8.712 8.8368.802 9.22 9.206 9.198 9.085 9.143 9.154 current (A) Working 31.92 30.4930.32 30.38 31.86 31.84 31.97 31.34 31.76 31.69 voltage (V) Working8.717 8.176 8.117 8.26 8.633 8.611 8.651 8.571 8.61 8.53 current (A)Power (W) 278.2 249.3 246.1 250.9 275 274.2 276.6 268.6 273.4 270.3

The fill factor refers to a ratio of the power at the maximum powerpoint of the solar cell module and the maximum power theoretically atzero resistance, and represents the proximity of the actual power withrespect to the theoretic maximum power, in which the greater the valueis, the higher the photoelectric conversion efficiency is. Generally,the series resistance is small, so the fill factor is great. Thephotoelectric conversion efficiency refers to a ratio of converting theoptical energy into electric energy by the module under a standardlighting condition (1000 W/m² of light intensity). The series resistanceis equivalent to the internal resistance of the solar module, in whichthe greater the value is, the poorer the performance of the module is.The fill factor represents a ratio of the actual maximum power and thetheoretical maximum power of the module, in which the greater the valueis, the better the performance of the module is. The open-circuitvoltage refers to the voltage of the module in an open circuit under astandard lighting condition. The short-circuit current refers to thecurrent of the module in a short circuit under a standard lightingcondition. The working voltage is the output voltage of the moduleworking with the largest power under a standard lighting condition. Theworking current is the output current of the module working with thelargest power under a standard lighting condition. The power is themaximum power which the module can reach under a standard lightingcondition.

It can be indicated from Table 1 that for the solar cell moduleaccording to the embodiments of the present disclosure, the metal wirewill not drift, and higher photoelectric conversion efficiency can beobtained.

Testing Example 22

(1) Welding a metal wire onto a surface of a cell, the metal wire beingin perpendicular to secondary grid lines of the cell;

(2) Placing the cell horizontally at a testing position of a tensiletester, and pressing blocks on the cell, in which the pressing blocksare disposed at two sides of the metal wire, such that the cell will notbe pulled up during the test;

(3) Clamping the metal wire at a pull ring of a tension meter that formsan angle of 45° with the cell;

(4) Actuating the tension meter, such that the tension meter movesuniformly along a vertical direction, pulls up the metal wire from thesurface of the cell and records the pull data tested, in which the datais averaged to obtain the pull data of the metal wire. The testingresult is shown in Table 4.

TABLE 4 Module A21 D21 D22 D23 A22 A23 A24 A25 A26 A27 Tensile force (N)0.45 0.38 0.25 0.26 0.34 0.33 0.39 0.48 0.43 0.37

It can be indicated from Table 4 that for the solar cell moduleaccording to the embodiments of the present disclosure, greater tensileforce is needed to pull the metal wire away from the upper gall of thecell, which proves stronger stability of connection between the metalwire and the cell in the solar cell module.

Example 31

Example 31 is used to illustrate the solar cell module 100 according tothe present application and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.04 mm², and the alloy layer has a thickness of 16 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module 100

A POE adhesive layer in 1630×980×0.5 mm is provided (melting point: 65°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness),each of which substantially runs through the cell 31 in a longitudinaldirection, and the distance between the adjacent secondary grid lines is1.7 mm. The cell 31 has five back electrodes (tin, 1.5 mm in width, 10μm in thickness) on its back surface. Each back electrode substantiallyruns through the cell 31 in a longitudinal direction, and the distancebetween the adjacent back electrodes is 31 mm.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under a strain. The metal wire extends reciprocally undera strain from two clips at two ends thereof, so as to form 15 parallelconductive wires. The secondary grid lines of the first cell 31 arewelded with the conductive wires and the back electrodes of the secondcell 31 are welded with the conductive wires at a welding temperature of160° C. The distance between parallel adjacent conductive wires is 9.9mm. 10 cells are connected in series into a row, and six rows of thecells of such kind are connected in series into a cell array via the busbar. The metal wire is cut off at the turns. Then, an upper glass plate,an upper POE adhesive layer, multiple cells arranged in a matrix formand welded with the metal wire, a lower POE adhesive layer and a lowerglass plate are superposed sequentially from up to down, in which theshiny surface of the cell 31 faces the front adhesive layer 20, suchthat the front adhesive layer 20 contacts with the conductive wires 32directly; and the shady surface of the cell 31 faces the back adhesivelayer 40, and finally they are laminated in a laminator, in which thefront adhesive layer 20 fills between adjacent conductive wires 32. Insuch way, a solar cell module A31 is obtained.

Comparison Example 31

The difference between Comparison example 31 and Example 31 lies in thatthe cells 31 are arranged in a matrix form, and in two adjacent cells,the fifteen parallel metal wires, by wiredrawing as shown in FIG. 17,are strained via the clips 34 at the ends of each metal wire, and thusthe cells are flattened at a strain of 2N of the clips. Each of thefifteen parallel metal wires is welded with secondary grid lines on afront surface of a first cell 31 respectively, and welded with backelectrodes on a back surface of a second cell 31. The distance betweenthe parallel adjacent conductive wires 32C is 9.9 mm (as shown in FIG.13). In such a way, a solar cell module D31 is obtained.

Comparison Example 32

The differences between Comparison example 32 and Comparison example 31lie in that the cells are arranged in a matrix form; 15 metal wiresconnected in series are pasted at a transparent adhesive layer, and themetal wires are attached to the solar cells. In two adjacent cells, themetal wire connects a front surface of a first cell and a back surfaceof a second cell. Then, an upper glass plate, an upper POE adhesivelayer, and a first transparent adhesive layer, multiple cells arrangedin a matrix form and welded with the metal wire, a second transparentadhesive layer, a lower POE adhesive layer and a lower glass plate aresuperposed sequentially from up to down. Thus, a solar cell module D32is obtained.

Example 32

Example 32 is used to illustrate the solar cell module 100 according tothe present application and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.03 mm², and the alloy layer has a thickness of 10 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module

A EVA adhesive layer in 1630×980×0.5 mm is provided (melting point: 60°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness) atits shiny surface, each of which substantially runs through the cell 31in a longitudinal direction, and the distance between the two adjacentsecondary grid lines is 1.7 mm. The cell 31 has five back electrodes(tin, 1.5 mm in width, 10 μm in thickness) on its back surface. Eachback electrode substantially runs through the cell 31 in thelongitudinal direction, and the distance between the two adjacent backelectrodes is 31 mm.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under a strain. The metal wire extends reciprocally undera strain from two clips at two ends thereof, so as to form 20 parallelconductive wires. The secondary grid lines of the first cell 31 arewelded with the conductive wires and the back electrodes of the secondcell 31 are welded with the conductive wires at a welding temperature of160° C. The distance between parallel adjacent conductive wires is 7 mm.10 cells are connected in series into a row, and six rows of the cellsof such kind are connected in series into a cell array via the bus bar.The metal wire is cut off at the turns. Then, an upper glass plate, anupper POE adhesive layer, multiple cells arranged in a matrix form andwelded with the metal wire, a lower POE adhesive layer and a lower glassplate are superposed sequentially from up to down, in which the shinysurface of the cell 31 faces the front adhesive layer 20, such that thefront adhesive layer 20 contacts with the conductive wires 32 directly;and the shady surface of the cell 31 faces the back adhesive layer 40,and finally they are laminated in a laminator, in which the frontadhesive layer 20 fills between adjacent conductive wires 32. In suchway, a solar cell module A32 is obtained.

Example 33

The solar cell module is manufactured according to the method in Example32, but the difference compared with Example 32 lies in that short gridlines 33 (silver, 0.1 mm in width) are disposed on the secondary gridlines 312 of the shiny surface of the cell 31, and are perpendicular tothe secondary grid lines 312 for connecting part of the secondary gridlines 312 at the edges of the shiny surface of the cell 31 with theconductive wires 32. As shown in FIG. 12, a solar cell module A33 isobtained.

Example 34

The solar cell module is manufactured according to the method in Example33, but the difference compared with Example 33 lies in that the cellarray is connected in such a manner that in two adjacent rows of cells,the conductive wires extend from a shiny surface of a cell at an end ofthe a^(th) row (a≧1) to form electrical connection with a back surfaceof a cell 31 at an adjacent end of the (a+1)^(th) row, so as to connectthe two adjacent rows of cells. The conductive wires for connecting thetwo adjacent rows of cells 31 are arranged in perpendicular to theconductive wires for connecting the adjacent cells 31 in the two rows.In such a way, a solar cell module A34 is obtained.

Testing Example 31

(1) Whether the metal wire in the solar cell module drifts is observedwith the naked eyes;

(2) According to the method disclosed in IEC904-1, the solar cellmodules manufactured in the above examples and the comparison exampleare tested with a single flash simulator under standard test conditions(STC): 1000 W/m² of light intensity, AM1.5 spectrum, and 25° C. Thephotoelectric conversion efficiency of each cell is recorded. Thetesting result is shown in Table 5.

TABLE 5 Solar cell module A31 D31 D32 A32 A33 A34 Metal wire no Slightlyno no no no drifting phenomenon Photoelectric 16.5% 15.6% 15.7 16.7%17.0% 17.2% conversion efficiency Series 458 493 482 445 433 429resistance (mΩ) Fill factor 0.779 0.759 0.756 0.783 0.790 0.794Open-circuit 37.65 37.54 37.63 37.75 37.86 37.88 voltage (V)Short-circuit 9.048 8.802 8.879 9.085 9.143 9.198 current (A) Working31.15 30.38 30.44 31.34 31.76 31.97 voltage (V) Working 8.520 8.26 8.2968.571 8.610 8.651 current (A) Power (W) 265.4 250.9 252.5 268.6 273.4276.6

The fill factor refers to a ratio of the power at the maximum powerpoint of the solar cell module and the maximum power theoretically atzero resistance, and represents the proximity of the actual power withrespect to the theoretic maximum power, in which the greater the valueis, the higher the photoelectric conversion efficiency is. Generally,the series resistance is small, so the fill factor is great. Thephotoelectric conversion efficiency refers to a ratio of converting theoptical energy into electric energy by the module under a standardlighting condition (1000 W/m² of light intensity). The series resistanceis equivalent to the internal resistance of the solar module, in whichthe greater the value is, the poorer the performance of the module is.The fill factor represents a ratio of the actual maximum power and thetheoretical maximum power of the module, in which the greater the valueis, the better the performance of the module is. The open-circuitvoltage refers to the voltage of the module in an open circuit under astandard lighting condition. The short-circuit current refers to thecurrent of the module in a short circuit under a standard lightingcondition. The working voltage is the output voltage of the moduleworking with the largest power under a standard lighting condition. Theworking current is the output current of the module working with thelargest power under a standard lighting condition. The power is themaximum power which the module can reach under a standard lightingcondition.

It can be indicated from Table 5 that for the solar cell moduleaccording to the embodiments of the present application, the metal wirewill not drift, and higher photoelectric conversion efficiency can beobtained.

Testing Example 32

(1) Welding a metal wire onto a surface of a cell, the metal wire beingin perpendicular to secondary grid lines of the cell;

(2) Placing the cell horizontally at a testing position of a tensiletester, and pressing blocks on the cell, in which the pressing blocksare disposed at two sides of the metal wire, such that the cell will notbe pulled up during the test;

(3) Clamping the metal wire at a pull ring of a tension meter that formsan angle of 45° with the cell;

(4) Actuating the tension meter, such that the tension meter movesuniformly along a vertical direction, pulls up the metal wire from thesurface of the cell and records the pull data tested, in which the datais averaged to obtain the pull data of the metal wire. The testingresult is shown in Table 6.

TABLE 6 Module A31 D31 D32 A32 A33 A34 Tensile force (N) 0.45 0.38 0.250.26 0.34 0.33

It can be indicated from Table 6 that for the solar cell moduleaccording to the embodiments of the present application, greater tensileforce is needed to pull the metal wire away from the upper gall of thecell, which proves stronger stability of connection between the metalwire and the cell in the solar cell module.

In the specification, it is to be understood that terms such as“central,” “longitudinal,” “lateral,” “length,” “width,” “thickness,”“upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,”“horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and“counterclockwise” should be construed to refer to the orientation asthen described or as shown in the drawings under discussion. Theserelative terms are for convenience of description and do not requirethat the present disclosure be constructed or operated in a particularorientation.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance or to imply the number of indicatedtechnical features. Thus, the feature defined with “first” and “second”may comprise one or more of this feature. In the description of thepresent disclosure, “a plurality of” means two or more than two, unlessspecified otherwise.

In the present disclosure, unless specified or limited otherwise, astructure in which a first feature is “on” or “below” a second featuremay include an embodiment in which the first feature is in directcontact with the second feature, and may also include an embodiment inwhich the first feature and the second feature are not in direct contactwith each other, but are contacted via an additional feature formedtherebetween. Furthermore, a first feature “on,” “above,” or “on top of”a second feature may include an embodiment in which the first feature isright or obliquely “on,” “above,” or “on top of” the second feature, orjust means that the first feature is at a height higher than that of thesecond feature; while a first feature “below,” “under,” or “on bottomof” a second feature may include an embodiment in which the firstfeature is right or obliquely “below,” “under,” or “on bottom of” thesecond feature, or just means that the first feature is at a heightlower than that of the second feature.

Reference throughout this specification to “an embodiment,” “someembodiments,” or “some examples” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, these terms throughout thisspecification do not necessarily refer to the same embodiment or exampleof the present disclosure. Furthermore, the particular features,structures, materials, or characteristics may be combined in anysuitable manner in one or more embodiments or examples.

Although embodiments of the present disclosure have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges, modifications, alternatives and variations can be made in theembodiments without departing from the scope of the present disclosure.

1-135. (canceled)
 136. A solar cell module, comprising an upper cover plate, a front adhesive layer, a cell array, a back adhesive layer and a back plate superposed in sequence, the cell array comprising multiple cells, adjacent cells connected by a plurality of conductive wires, at least two conductive wires comprising a metal wire which extends reciprocally between surfaces of adjacent cells, the conductive wires being in contact with the cells, the front adhesive layer in direct contact with the conductive wires and disposed between adjacent conductive wires.
 137. The solar cell module according to claim 136, wherein the metal wire extends reciprocally between a front surface of a first cell and a back surface of a second cell adjacent to the first cell; the front adhesive layer contacts with the conductive wires on the front surface of the first cell directly and is disposed between the adjacent conductive wires on the front surface of the first cell; the back adhesive layer contacts with the conductive wires on the back surface of the second cell directly and is disposed between the adjacent conductive wires on the back surface of the second cell.
 138. The solar cell module according to claim 137, wherein the conductive wires disposed on the back surface of the second cell are electrically connected with back electrodes of the second cell.
 139. The solar cell module according to claim 136, wherein the metal wire extends reciprocally for 10 to 60 times to form 20 to 120 conductive wires.
 140. The solar cell module according to claim 136, wherein a distance between adjacent conductive wires ranges from 2.5 mm to 15 mm.
 141. The solar cell module according to claim 136, wherein the adjacent conductive wires form a U-shape structure or a V-shape structure.
 142. The solar cell module according to claim 136, wherein there is only one metal wire.
 143. The solar cell module according to claim 136, wherein the metal wire is a copper wire.
 144. The solar cell module according to claim 136, wherein the metal wire has a circular cross section.
 145. The solar cell module according to claim 136, wherein the metal wire extends reciprocally under strain, before contacting with the cells.
 146. The solar cell module according to claim 136, wherein a binding force between the metal wire and the cells ranges from 0.1 N to 0.8 N.
 147. The solar cell module according to claim 146, wherein the binding force between the metal wire and the cells ranges from 0.2N to 0.6N.
 148. The solar cell module according to claim 136, wherein the cell has a dimension of 156 mm×156 mm; and the solar cell module has a series resistance of 380 to 440 mΩ per 60 cells.
 149. The solar cell module according claim 136, wherein the cell has a dimension of 156 mm×156 mm; and the solar cell module has an open-circuit voltage of 37.5-38.5 V per 60 cells, and a short-circuit current 8.9-9.4 A.
 150. The solar cell module according to claim 136, wherein the solar cell module has a fill factor of 0.79 to 0.82.
 151. The solar cell module according to claim 136, wherein the cell has a dimension of 156 mm×156 mm; and the solar cell module has a working voltage of 31.5-32 V per 60 cells, and a working current of 8.4-8.6 A.
 152. The solar cell module according to claim 136, wherein the cell has a dimension of 156 mm×156 mm; and the solar cell module has a conversion efficiency of 16.5-17.4%, and a power of 265-280 W per 60 cells.
 153. A method for manufacturing a solar cell module, comprising: forming at least two conductive wires by a metal wire which extends reciprocally between surfaces of cells and contacts with the surfaces of the cells, such that the adjacent cells are connected by a plurality of conductive wires to constitute a cell array; superposing an upper cover plate, a front adhesive layer, the cell array, a back adhesive layer and a back plate in sequence, in which a front surface of the cell faces the front adhesive layer, such that the front adhesive layer contacts with the conductive wires directly and is disposed between adjacent conductive wires; and a back surface of the cell faces the back adhesive layer; and laminating the superposed layers to obtain the solar cell module.
 154. The method according to claim 153, wherein the metal wire extends reciprocally under strain before contacting with the cells.
 155. The method according to claim 153, wherein the metal wire extends reciprocally between a front surface of a first cell and a back surface of a second cell, such that the front adhesive layer directly contacts with the conductive wires on the front surface of the first cell; and the back adhesive layer directly contacts with the conductive wires on the back surface of the second cell. 